@article{https://doi.org/10.1002/pssa.201900590,

title = {Mechanical and Electronic Properties of Tin Carbide Nanowires},

author = {Alma L. Marcos-Viquez and \'{A}lvaro Miranda and Miguel Cruz-Irisson and Luis A. P\'{e}rez},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/pssa.201900590},

doi = {https://doi.org/10.1002/pssa.201900590},

year  = {2020},

date = {2020-01-01},

journal = {physica status solidi (a)},

volume = {217},

number = {5},

pages = {1900590},

abstract = {Herein, the mechanical and electronic properties of tin carbide nanowires (NWs) with zinc-blende structure are theoretically investigated using density functional calculations within the generalized gradient approximation. The axes of the studied NWs, which have hexagonal cross sections of six different sizes, are taken along the [111] crystallographic direction, and their surfaces are passivated with either hydrogen or fluorine. The effects of diameter size and chemical passivation on the cohesive energy, electronic structure, and Young's modulus of the various studied NWs are discussed. Moreover, the results obtained are compared with those corresponding to silicon and silicon carbide NWs with similar structures. Finally, the adsorption of carbon monoxide (CO) and nitric oxide (NO) molecules on tin carbide NWs is addressed.},

keywords = {density functional theory calculations, electronic band structures, Gas sensors, silicon carbide nanowires, tin carbide nanowires, Young's moduli},

pubstate = {published},

tppubtype = {article}

}

@article{GONZALEZ2020109136,

title = {Thermoelectric transport in poly(G)-poly(C) double chains},

author = {J. E. Gonz\'{a}lez and M. Cruz-Irisson and V. S\'{a}nchez and C. Wang},

url = {https://www.sciencedirect.com/science/article/pii/S0022369719315550},

doi = {https://doi.org/10.1016/j.jpcs.2019.109136},

issn = {0022-3697},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Physics and Chemistry of Solids},

volume = {136},

pages = {109136},

abstract = {Electronic and phononic transport in DNA systems with macroscopic length are studied by means of a real-space renormalization method within the Boltzmann formalism, where the poly(G)-poly(C) base-pair segments arranged following periodic and Fibonacci sequences are comparatively analyzed. The fishbone model and the two-site coarse grain model based on the Born potential including central and non-central interactions are respectively used for the calculation of electrical and lattice thermal conductivities of these DNA systems connected to two reservoirs at their ends. The results show the appearance of gaps in phononic transmittance spectra of segmented poly(G)-poly(C) double chains, which leads to a better thermoelectric figure of merit (ZT) than that of corresponding non-segmented systems. Such ZT can be further improved by introducing a long-range quasiperiodic order, which avoids the thermal transport of numerous low-frequency phonons responsible of the lattice thermal conduction at low temperature. Finally, the influence of reservoirs on ZT is also investigated.},

keywords = {Electronic transport, Organic semiconductors, Quasiperiodicity, Thermoelectricity},

pubstate = {published},

tppubtype = {article}

}

@article{Salazar2019,

title = {Interstitial sodium and lithium doping effects on the electronic and mechanical properties of silicon nanowires: a DFT study},

author = {F. Salazar and A. Trejo-Ba\~{n}os and A. Miranda and L. A. P\'{e}rez and M Cruz-Irisson},

url = {https://doi.org/10.1007/s00894-019-4239-5},

doi = {10.1007/s00894-019-4239-5},

issn = {0948-5023},

year  = {2019},

date = {2019-11-09},

journal = {Journal of Molecular Modeling},

volume = {25},

number = {11},

pages = {338},

abstract = {In this work, we present a theoretical study of the electronic band structure and the Young's modulus of hydrogen-passivated silicon nanowires (H-SiNWs), grown along the [110] crystallographic direction, as a function of the concentration of interstitial sodium (Na) and lithium (Li) atoms. The study is performed using the supercell scheme and the density functional theory (DFT), within the local density approximation (LDA). The results show that the presence of Na or Li atoms closes the former semiconducting band gap of the H-SiNWs and shifts the Fermi energy into the conduction band. The transition from semiconductor to metal occurs as soon as a single Na or Li atom is added to the nanowire and the number of occupied states near the Fermi level is larger for the H-SiNWs with Li atoms in comparison with those nanowires with the same concentration of Na atoms. The calculated formation energies reveal that the system becomes less stable when the concentration of Na and Li atoms augments. Moreover, the obtained binding energies indicate that Si--Li and Si--Na bonds are formed. It is worth mentioning that the binding energies of H-SiNWs with interstitial Li atoms are larger than those corresponding to the H-SiNWs with interstitial Na atoms. On the other hand, the Young's moduli of H-SiNWs with Na atoms are lower than those of pure H-SiNWs and their values diminish when the concentration of Na atoms increases. In contrast, Young's moduli of H-SiNWs present a non-monotonic behavior as a function of the concentration of interstitial Li atoms and for the largest studied concentration the nanowire fractures. These results give insight into the changes that electronic and mechanical properties of H-SiNWs suffer during the charge-discharge process, which should be taken into account in the design of electrodes of Na or Li-ion batteries.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gonz\'{a}lez_2019,

title = {Confinement effect on the low temperature specific heat for ultrathin silicon nanowires: a first principles study},

author = {I Gonz\'{a}lez and M Calvino and A Trejo and F Salazar and M Cruz-Irisson},

url = {https://dx.doi.org/10.1088/1361-648X/ab2dd4},

doi = {10.1088/1361-648X/ab2dd4},

year  = {2019},

date = {2019-07-01},

journal = {Journal of Physics: Condensed Matter},

volume = {31},

number = {42},

pages = {425303},

publisher = {IOP Publishing},

abstract = {This work studied the phonon confinement effects at the low temperature specific heat of Si nanowires from first principles using density functional perturbation theory. The nanowires were modeled in the [0 0 1] direction for three different diameters, with the largest cross section being approximately 10 r{A}. The results indicate the specific heat can be described at low temperatures using a third-grade polynomial of the form cv = λT + βT2 + γT3, where the coefficients of quadratic and cubic terms are almost nonexistent for small diameters. These terms begin to have relevance at larger diameters. Further analysis shows λ \> β \> γ, which shows the phonon confinement (λ) and surface atoms (β) become more important than the volumetric contribution (γ) for ultrathin nanowires at low temperatures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{DESANTIAGO2019278,

title = {Quasi-one-dimensional silicon nanostructures for gas molecule adsorption: a DFT investigation},

author = {Francisco Santiago and Jos\'{e} Eduardo Santana and \'{A}lvaro Miranda and Alejandro Trejo and Rub\'{e}n V\'{a}zquez-Medina and Luis Antonio P\'{e}rez and Miguel Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0169433218336109},

doi = {https://doi.org/10.1016/j.apsusc.2018.12.258},

issn = {0169-4332},

year  = {2019},

date = {2019-01-01},

journal = {Applied Surface Science},

volume = {475},

pages = {278-284},

abstract = {Porous structures offer an enormous surface suitable for gas sensing, however, the effects of their quantum quasi-confinement on their molecular sensing capacities has been seldom studied. In this work the gas-sensing capability of silicon nanopores is investigated by comparing it to silicon nanowires using first principles calculations. In particular, the adsorption of toxic gas molecules CO, NO, SO2 and NO2 on both silicon nanopores and nanowires with the same cross sections was studied. Results show that sensing-related properties of silicon nanopores and nanowires are very similar, suggesting that surface effects are predominant over the confinement. However, there are certain cases where there are remarked differences between the nanowire and porous cases, for instance, CO-adsorbed nanoporous silicon shows a metallic band structure unlike its nanowire counterpart, which remains semiconducting, suggesting that quantum quasi-confinement may be playing an important role in this behaviour. These results are significant in the study of the quantum phenomena behind the adsorption of gas molecules on nanostructure’s surfaces, with possible applications in chemical detectors or catalysts.},

keywords = {Chemical sensors, Density Functional Theory, Molecule adsorption, porous silicon, Sensing, Silicon nanowires},

pubstate = {published},

tppubtype = {article}

}

@article{DESANTIAGO2019438,

title = {Lithiation effects on the structural and electronic properties of Si nanowires as a potential anode material},

author = {F. De Santiago and J. E. Gonz\'{a}lez and A. Miranda and A. Trejo and F. Salazar and L. A. P\'{e}rez and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S2405829718313254},

doi = {https://doi.org/10.1016/j.ensm.2019.04.023},

issn = {2405-8297},

year  = {2019},

date = {2019-01-01},

journal = {Energy Storage Materials},

volume = {20},

pages = {438-445},

abstract = {The need for better energy-storage materials has attracted much attention to the development of Li-ion battery electrodes. Si nanowires have been considered as alternative electrodes, however the effects of Li on their electronic band gap and mechanical properties have been scarcely studied. In this work, a density functional study of the electronic and mechanical properties of hydrogen passivated silicon nanowires (H-SiNWs) grown along the [001] direction is presented. The Li atoms are gradually inserted at interstitial positions or replacing surface H atoms. The results show that, for surface-lithiated H-SiNWs, the semiconducting band gap decreases when the concentration of Li atoms increases; whereas the H-SiNWs become metallic even with the addition of only one interstitial Li atom. The formation energy diminishes with the concentration of Li atoms for surface-lithiated H-SiNWs, whereas the contrary behavior is found in the interstitial-lithiated H-SiNWs. Furthermore, for the surface-lithiation case, the Li binding energy reveals the existence of SiLi bonds, whereas for the interstitial-lithiation case, the Li binding energy increases when the Li grows up to a critical concentration, where some SiSi bonds break. Finally, for the case of surface-lithiation, the Young's modulus (Y) increases with the concentration of Li, whereas for the interstitial-lithiation case, Y suffers a sudden diminution at a certain Li concentration due to the large internal mechanical stresses within the nanowire structure. These results should be considered when regarding H-SiNWs as potential electrodes in Li-ion battery anodes.},

keywords = {electronic properties, Li batteries, Silicon nanowires, Young's modulus},

pubstate = {published},

tppubtype = {article}

}

@article{Gonz\'{a}lez-Mac\'{i}as2018,

title = {Theoretical study of the mechanical and electronic properties of [111]-Si nanowires with interstitial lithium},

author = {A. Gonz\'{a}lez-Mac\'{i}as and F. Salazar and A. Miranda and A. Trejo and I. J. Hern\'{a}ndez-Hern\'{a}ndez and L. A. P\'{e}rez and M Cruz-Irisson},

url = {https://doi.org/10.1007/s10854-018-9331-6},

doi = {10.1007/s10854-018-9331-6},

issn = {1573-482X},

year  = {2018},

date = {2018-09-01},

journal = {Journal of Materials Science: Materials in Electronics},

volume = {29},

number = {18},

pages = {15795-15800},

abstract = {In this work, we present a density functional study of the Young's modulus and electronic properties of hydrogen passivated silicon nanowires (H-SiNWs) grown along [111] crystallographic direction as function of concentration of interstitial lithium (Li) atoms. The study is performed using the supercell scheme, within the local density approximation implemented in the SIESTA code. The results show that the presence of Li closes the known semiconductor band gap of the H-SiNWs showing a like metallic behavior even when just one Li atom is placed in the nanowire structure. The participation of the Li atoms in the electronic density of states is almost constant in the valence and conduction bands. The formation energy analysis show how the system loses energetic stability when the concentration of Li grows, while the binding energy per Li atom suggests the formation of Si--Li bonds. On the other hand, the Young's modulus of the silicon nanowires (SiNWs) is higher than that of the H-SiNW and lower than the bulk value. Moreover, the Young's modulus is almost constant independently of the Li concentration. This result indicates that the H-SiNWs support the internal stress due to the addition of Li atoms and could offer a better useful life as electrodes in Li-ion batteries. The results of this work help to understand how the electronic and mechanical properties of H-SiNWs change during the charge/discharge process and the possibility to incorporate them as electrodes in Li batteries.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{deSantiago_2018,

title = {Carbon monoxide sensing properties of B-, Al- and Ga-doped Si nanowires},

author = {F Santiago and A Trejo and A Miranda and F Salazar and E Carvajal and L A P\'{e}rez and M Cruz-Irisson},

url = {https://dx.doi.org/10.1088/1361-6528/aab237},

doi = {10.1088/1361-6528/aab237},

year  = {2018},

date = {2018-03-01},

journal = {Nanotechnology},

volume = {29},

number = {20},

pages = {204001},

publisher = {IOP Publishing},

abstract = {Silicon nanowires (SiNWs) are considered as potential chemical sensors due to their large surface-to-volume ratio and their possible integration into arrays for nanotechnological applications. Detection of harmful gases like CO has been experimentally demonstrated, however, the influence of doping on the sensing capacity of SiNWs has not yet been reported. For this work, we theoretically studied the surface adsorption of a CO molecule on hydrogen-passivated SiNWs grown along the [111] crystallographic direction and compared it with the adsorption of other molecules such as NO, and O2. Three nanowire diameters and three dopant elements (B, Al and Ga) were considered, and calculations were done within the density functional theory framework. The results indicate that CO molecules are more strongly adsorbed on the doped SiNW than on the pristine SiNW. The following trend was observed for the CO adsorption energies: EA[B-doped] \> EA[Al-doped] \> EA[Ga-doped] \> EA[undoped], for all diameters. The electronic charge transfers between the SiNWs and the adsorbed CO were estimated by using a Voronoi population analysis. The CO adsorbed onto the undoped SiNWs has an electron-acceptor character, while the CO adsorbed onto the B-, Al-, and Ga-doped SiNWs exhibits an electron-donor character. Comparing these results with the ones obtained for the NO and O2 adsorption, the larger CO adsorption energy on B-doped SiNWs indicates their good selectivity towards CO. These results suggest that SiNW-based sensors of toxic gases could represent a clear and advantageous application of nanotechnology in the improvement of human quality of life.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Gonz\'{a}lez-Mac\'{i}as_2018,

title = {Lithium effects on the mechanical and electronic properties of germanium nanowires},

author = {A Gonz\'{a}lez-Mac\'{i}as and F Salazar and A Miranda and A Trejo-Ba\~{n}os and L A P\'{e}rez and E Carvajal and M Cruz-Irisson},

url = {https://dx.doi.org/10.1088/1361-6528/aaaad4},

doi = {10.1088/1361-6528/aaaad4},

year  = {2018},

date = {2018-02-01},

journal = {Nanotechnology},

volume = {29},

number = {15},

pages = {154004},

publisher = {IOP Publishing},

abstract = {Semiconductor nanowire arrays promise rapid development of a new generation of lithium (Li) batteries because they can store more Li atoms than conventional crystals due to their large surface areas. During the charge\textendashdischarge process, the electrodes experience internal stresses that fatigue the material and limit the useful life of the battery. The theoretical study of electronic and mechanical properties of lithiated nanowire arrays allows the designing of electrode materials that could improve battery performance. In this work, we present a density functional theory study of the electronic band structure, formation energy, binding energy, and Young’s modulus (Y) of hydrogen passivated germanium nanowires (H\textendashGeNWs) grown along the [111] and [001] crystallographic directions with surface and interstitial Li atoms. The results show that the germanium nanowires (GeNWs) with surface Li atoms maintain their semiconducting behavior but their energy gap size decreases when the Li concentration grows. In contrast, the GeNWs can have semiconductor or metallic behavior depending on the concentration of the interstitial Li atoms. On the other hand, Y is an indicator of the structural changes that GeNWs suffer due to the concentration of Li atoms. For surface Li atoms, Y stays almost constant, whereas for interstitial Li atoms, the Y values indicate important structural changes in the GeNWs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{C8DT00355F,

title = {Lithium effect on the electronic properties of porous silicon for energy storage applications: a DFT study},

author = {I. Gonz\'{a}lez and A. N. Sosa and A. Trejo and M. Calvino and A. Miranda and M. Cruz-Irisson},

url = {http://dx.doi.org/10.1039/C8DT00355F},

doi = {10.1039/C8DT00355F},

year  = {2018},

date = {2018-01-01},

journal = {Dalton Trans.},

volume = {47},

issue = {22},

pages = {7505-7514},

publisher = {The Royal Society of Chemistry},

abstract = {Theoretical studies on the effect of Li on the electronic properties of porous silicon are still scarce; these studies could help us in the development of Li-ion batteries of this material which overcomes some limitations that bulk silicon has. In this work, the effect of interstitial and surface Li on the electronic properties of porous Si is studied using the first-principles density functional theory approach and the generalised gradient approximation. The pores are modeled by removing columns of atoms of an otherwise perfect Si crystal, dangling bonds of all surfaces are passivated with H atoms, and then Li is inserted on interstitial positions on the pore wall and compared with the replacement of H atoms with Li. The results show that the interstitial Li creates effects similar to n-type doping where the Fermi level is shifted towards the conduction band with band crossings of the said level thus acquiring metallic characteristics. The surface Li introduces trap-like states in the electronic band structures which increase as the number of Li atom increases with a tendency to become metallic. These results could be important for the application of porous Si nanostructures in Li-ion batteries technology.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{CUEVAS2018268,

title = {First principles band gap engineering of [1 1 0] oriented 3C-SiC nanowires},

author = {Jos\'{e} Luis Cuevas and Francisco Santiago and Jes\'{u}s Ram\'{i}rez and Alejandro Trejo and \'{A}lvaro Miranda and Luis Antonio P\'{e}rez and Miguel Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0927025617305712},

doi = {https://doi.org/10.1016/j.commatsci.2017.10.021},

issn = {0927-0256},

year  = {2018},

date = {2018-01-01},

journal = {Computational Materials Science},

volume = {142},

pages = {268-276},

abstract = {Silicon carbide nanowires offer excellent opportunities for technological applications under harsh environmental conditions, however, the 3C-SiC polytype nanowires, grown along the [1 1 0] crystallographic direction, have been rarely studied, as well as the effects of the surface passivation on their physical properties. This work addresses the effects of hydrogen passivation on the electronic band gap of silicon carbide nanowires (SiCNWs) grown along the [1 1 0] direction by means of Density Functional Theory. We compare the electronic properties of fully hydrogen-passivated SiCNWs in comparison to those of SiCNWs with a mixed passivation of oxygen and hydrogen by changing some of the surface dihydrides with SiOSi or COC bonds. The results show that regardless of the diameter and passivation, most of the nanowires have a direct band gap which suggests an increased optical activity. The surface COC bonds reduce the electronic band gap energy compared to that of the fully H-terminated phase, while the nanowires with SiOSi bonds have a larger band gap. The calculation of formation energies shows that the oxygen increases the chemical stability of the SiCNWs. These results indicate the possibility of band gap engineering on SiC nanostructures through surface passivation.},

keywords = {DFT, Formation energy, SiC nanowires, Surface passivation},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/qua.25713,

title = {Quantum confinement effects on the harmful-gas-sensing properties of silicon nanowires},

author = {Francisco Santiago and \'{A}lvaro Miranda and Alejandro Trejo and Fernando Salazar and Eliel Carvajal and Miguel Cruz-Irisson and Luis A. P\'{e}rez},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qua.25713},

doi = {https://doi.org/10.1002/qua.25713},

year  = {2018},

date = {2018-01-01},

journal = {International Journal of Quantum Chemistry},

volume = {118},

number = {20},

pages = {e25713},

abstract = {Abstract In this work, the effects of the adsorption of different toxic gas molecules CO, NO, NO2, and SO2 on the electronic structure of hydrogen-passivated, [111]-oriented, silicon nanowires (H-SiNWs), are studied through density functional theory. To analyze the effects of quantum confinement, three nanowire diameters are considered. The results show that the adsorption energies are almost independent of the nanowire diameter with NO2 being the most strongly adsorbed molecule (∼3.44 eV). The electronic structure of small-diameter H-SiNWs is modified due to the creation of isolated defect-like states on molecule adsorption. However, these discrete levels are eventually hybridized with the former nanowire states as the nanowire diameter increases and quantum confinement effects become less evident. Hence, there is a range of small nanowire diameters with distinctive band gaps and adsorption energies for each molecule species.},

keywords = {Density Functional Theory, Nanowires, Sensors, silicon, toxic gases},

pubstate = {published},

tppubtype = {article}

}

@article{GONZALEZ2018420,

title = {Effects of surface and confinement on the optical vibrational modes and dielectric function of 3C porous silicon carbide: An ab-initio study},

author = {I. Gonz\'{a}lez and A. Trejo and M. Calvino and A. Miranda and F. Salazar and E. Carvajal and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0921452618303569},

doi = {https://doi.org/10.1016/j.physb.2018.05.024},

issn = {0921-4526},

year  = {2018},

date = {2018-01-01},

journal = {Physica B: Condensed Matter},

volume = {550},

pages = {420-427},

abstract = {Nanoporous silicon carbide is an interesting material with multiple potential applications, especially in supercapacitors, while there are many experimental investigations on the properties of this material, theoretical studies on its vibrational and optical properties are still scarce. This work studies the effect of quantum confinement on the dielectric function and optical vibrational modes of 3C porous silicon carbide from ab-initio calculations using density functional theory and density functional perturbation theory. The porous structures are modelled in the [001] direction by removing columns of atoms of a perfect Si crystal, obtaining two surface configurations: one with only C atoms and another one with Si atoms. Results show that the optical phonon modes of Si and C undergo a shift towards lower frequencies compared to their bulk counterparts due to phonon confinement effects. However, this shift is masked by H bending vibrations. Also, a surface H exchange process is observed on the Si-rich pore surface due to bond stretching and bending vibrations. The dielectric function analysis shows an increased optical activity in the porous cases due to a shift of the conduction band minimum towards gamma point for the C-rich case and high porosity Si-rich case, owing to quantum confinement effects. These results could be important for the applications of these nanostructures devices such as sensors and UV detectors.},

keywords = {DFPT, Dielectric function, Phonon optical modes, Porous silicon carbide},

pubstate = {published},

tppubtype = {article}

}

@article{Pilo2017,

title = {Bidimensional perovskite systems for spintronic applications},

author = {Jorge Pilo and \'{A}lvaro Miranda and Alejandro Trejo and Eliel Carvajal and Miguel Cruz-Irisson},

url = {https://doi.org/10.1007/s00894-017-3483-9},

doi = {10.1007/s00894-017-3483-9},

issn = {0948-5023},

year  = {2017},

date = {2017-10-24},

journal = {Journal of Molecular Modeling},

volume = {23},

number = {11},

pages = {322},

abstract = {The half-metallic behavior of the perovskite Sr2FeMoO6 (SFMO) suggests that this material could be used in spintronic applications. Indeed, SFMO could be an attractive material for multiple applications due to the possibility that its electronic properties could be changed by modifying its spatial confinement or the relative contents of its constituent transition metals. However, there are no reports of theoretical studies on the properties of confined SFMOs with different transition metal contents. In this work, we studied the electronic properties of SFMO slabs using spin-polarized first-principles density functional theory along with the Hubbard-corrected local density approximation and a supercell scheme. We modeled three insulated SFMO slabs with Fe:Mo atomic ratios of 1:1, 1:0, and 0:1; all with free surfaces parallel to the (001) crystal plane. The results show that the half-metallicity of the SFMO is lost upon confinement and the material becomes a conductor, regardless of the ratio of Fe to Mo. It was also observed that the magnetic moment of the slab is strongly influenced by the oxygen atoms. These results could prove useful in attempts to apply SFMOs in fields other than spintronics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{deSantiago2017,

title = {Band-gap engineering of halogenated silicon nanowires through molecular doping},

author = {Francisco Santiago and Alejandro Trejo and Alvaro Miranda and Eliel Carvajal and Luis Antonio P\'{e}rez and Miguel Cruz-Irisson},

url = {https://doi.org/10.1007/s00894-017-3484-8},

doi = {10.1007/s00894-017-3484-8},

issn = {0948-5023},

year  = {2017},

date = {2017-10-16},

journal = {Journal of Molecular Modeling},

volume = {23},

number = {11},

pages = {314},

abstract = {In this work, we address the effects of molecular doping on the electronic properties of fluorinated and chlorinated silicon nanowires (SiNWs), in comparison with those corresponding to hydrogen-passivated SiNWs. Adsorption of n-type dopant molecules on hydrogenated and halogenated SiNWs and their chemisorption energies, formation energies, and electronic band gap are studied by using density functional theory calculations. The results show that there are considerable charge transfers and strong covalent interactions between the dopant molecules and the SiNWs. Moreover, the results show that the energy band gap of SiNWs changes due to chemical surface doping and it can be further tuned by surface passivation. We conclude that a molecular based ex-situ doping, where molecules are adsorbed on the surface of the SiNW, can be an alternative path to conventional doping.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Solano2017,

title = {DFT study of anisotropy effects on the electronic properties of diamond nanowires with nitrogen-vacancy center},

author = {Jes\'{u}s Ram\'{i}rez Solano and Alejandro Trejo Ba\~{n}os and \'{A}lvaro Miranda Dur\'{a}n and Eliel Carvajal Quiroz and Miguel Cruz Irisson},

url = {https://doi.org/10.1007/s00894-017-3462-1},

doi = {10.1007/s00894-017-3462-1},

issn = {0948-5023},

year  = {2017},

date = {2017-09-26},

journal = {Journal of Molecular Modeling},

volume = {23},

number = {10},

pages = {292},

abstract = {In the development of quantum computing and communications, improvements in materials capable of single photon emission are of great importance. Advances in single photon emission have been achieved experimentally by introducing nitrogen-vacancy (N-V) centers on diamond nanostructures. However, theoretical modeling of the anisotropic effects on the electronic properties of these materials is almost nonexistent. In this study, the electronic band structure and density of states of diamond nanowires with N-V defects were analyzed through first principles approach using the density functional theory and the supercell scheme. The nanowires were modeled on two growth directions [001] and [111]. All surface dangling bonds were passivated with hydrogen (H) atoms. The results show that the N-V introduces multiple trap states within the energy band gap of the diamond nanowire. The energy difference between these states is influenced by the growth direction of the nanowires, which could contribute to the emission of photons with different wavelengths. The presence of these trap states could reduce the recombination rate between the conduction and the valence band, thus favoring the single photon emission.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{MIRANDA20171246,

title = {Silicon nanowires as potential gas sensors: A density functional study},

author = {A. Miranda and F. Santiago and L. A. P\'{e}rez and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0925400516315106},

doi = {https://doi.org/10.1016/j.snb.2016.09.085},

issn = {0925-4005},

year  = {2017},

date = {2017-01-01},

urldate = {2017-01-01},

journal = {Sensors and Actuators B: Chemical},

volume = {242},

pages = {1246-1250},

abstract = {Silicon nanowires (SiNWs) have chemical sensitivity to molecules such as NH3 and NO2. Yet, SiNWs have not been considered for sensing harmful gases such as CO, CO2, NO, SO2, and HCN. In this work, we theoretically address the capability of SiNWs, grown along the [111] crystallographic direction and with a diameter of 1.5nm, as molecular sensors to detect these gases. The density functional theory calculations indicate that CO, NO, NO2, and SO2 molecules can be adsorbed on the SiNWs surface with energies ranging from 0.07eV to 3.41eV. However, we have also found that SiNWs are not good candidates for sensing CO2 and HCN molecules.},

keywords = {Density Functional Theory, Gas sensing, Molecular adsorption, Silicon nanowires},

pubstate = {published},

tppubtype = {article}

}

@article{Escamilla2016,

title = {XPS study of the electronic density of states in the superconducting Mo2B and Mo2BC compounds},

author = {R. Escamilla and E. Carvajal and M. Cruz-Irisson and F. Morales and L. Huerta and E. Verdin},

url = {https://doi.org/10.1007/s10853-016-9938-z},

doi = {10.1007/s10853-016-9938-z},

issn = {1573-4803},

year  = {2016},

date = {2016-07-01},

urldate = {2016-07-01},

journal = {Journal of Materials Science},

volume = {51},

number = {13},

pages = {6411-6418},

abstract = {The electronic structure of the Mo$$_2$$BC and Mo$$_2$$B compounds was investigated by X-ray photoelectron spectroscopy. The Mo 3d, C 1s, and B 1s core levels are identified. For the Mo$$_2$$BC, the core-level binding energies corresponding to Mo 3d$$_5/2$$, B 1s, and C 1s are localized at 227.90, 187.94, and 282.95 eV, respectively, whereas for the Mo$$_2$$B, the Mo 3d$$_5/2$$, and B 1s are localized at 228.09 and 188.06 eV, respectively. Core-level binding energies shifts are observed in both compounds using the charge-potential model. The electronic density of states was calculated for Mo$$_2$$B and Mo$$_2$$BC using GGA approximation. Our results show that the electronic density of states at the Fermi level in the Mo$$_2$$B is higher than that in the Mo$$_2$$BC. The dominance of the Mo 4d states down to 8 eV below the Fermi level is found. The calculated total DOS was consistent with the XPS valence band spectra. Finally, within the BCS theory framework, the presence of superconductivity in both compounds can not be explained only as a function of the electronic density of states at the Fermi level. The electron-phonon coupling constant ($$backslashlambda $$) was calculated using the McMillan equation; the obtained values were 0.75 for Mo$$_2$$BC and 0.70 for Mo$$_2$$B. These values indicate that both compounds are intermediate coupled superconductors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Calvino2016,

title = {Modeling the effects of Si-X (X = F, Cl) bonds on the chemical and electronic properties of Si-surface terminated porous 3C-SiC},

author = {Marbella Calvino and Alejandro Trejo and Margarita Clarisaila Cris\'{o}stomo and Mar\'{i}a Isabel Iturrios and Eliel Carvajal and M Cruz-Irisson},

url = {https://doi.org/10.1007/s00214-016-1861-5},

doi = {10.1007/s00214-016-1861-5},

issn = {1432-2234},

year  = {2016},

date = {2016-03-26},

journal = {Theoretical Chemistry Accounts},

volume = {135},

number = {4},

pages = {104},

abstract = {Porous silicon carbide offers a great potential as a sensor material for applications in medicine and energetics; however, the theoretical chemical characterization of its surface is almost nonexistent, and a correct understanding of its chemical properties could lead to the development of better applications of this nanostructure. Hence, a study of the effects of different passivation agents on the structure and electronic properties of porous silicon carbide by means of density functional theory and the supercell technique was developed. The porous structures were modeled by removing columns of atoms of an otherwise perfect SiC crystal in the [001] direction, so that the porous structure exhibits a surface exclusively composed of Si atoms (Si-rich) using different surface passivation agents, such as hydrogen (H), fluoride (F) and chloride (Cl). The results demonstrate that all of the passivation schemes exhibit an irregular band gap energy evolution due to a hybridization change of the surface. The structural analysis shows a great dependence of the bond characteristics on the electronegativity of the bonded atoms, and all of the structural and electronic changes could be explained due to steric effects. These results could be important in the characterization of pSiC because they provide insight into the most stable surface configurations and their electronic structures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{TREJO2016215,

title = {Optical vibrational modes of Ge nanowires: A computational approach},

author = {A. Trejo and A. Miranda and L. K. Toscano-Medina and R. V\'{a}zquez-Medina and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0167931716302258},

doi = {https://doi.org/10.1016/j.mee.2016.04.024},

issn = {0167-9317},

year  = {2016},

date = {2016-01-01},

journal = {Microelectronic Engineering},

volume = {159},

pages = {215-220},

abstract = {Although Ge nanowires (GeNWs) have been extensively studied in the last decade the information about their vibrational modes is still scarce, their correct comprehension could hasten the development of new microelectronic technologies, therefore, in this work we aimed to study the vibrational properties, Raman and IR and spectrum of GeNWs using the first principles density functional perturbation theory. The nanowires are modelled in the [001] direction and all dangling bonds are passivated with H and Cl atoms. Results show that the vibrational modes can be classified in three frequency intervals, a low frequency one (between 0 and 300cm−1) of mainly GeGe vibrations, and two of GeH bending and stretching vibrations (400\textendash500cm−1 and 2000cm−1, respectively). There is a shift of the highest optical modes of GeGe vibrations compared to their bulk counterparts due to phonon confinement effects, however it is masked by some GeH bond bending modes as demonstrated by the IR and Raman responses. The Cl passivated case shows a larger number of modes at lower frequencies due to the higher mass of Cl compared to H, which in turn reduces the red shift of the highest optical modes frequencies. These results could be important for the characterization of GeNWs with different surface passivations.},

note = {Micro/Nano Devices and Systems 2015},

keywords = {Density functional perturbation theory, Germanium nanowires, Phonons, Raman spectrum},

pubstate = {published},

tppubtype = {article}

}

@article{PILO2016110,

title = {Effect of the transition metal ratio on bulk and thin slab double perovskite Sr2FeMoO6},

author = {J. Pilo and A. Trejo and E. Carvajal and R. Oviedo-Roa and M. Cruz-Irisson and O. Navarro},

url = {https://www.sciencedirect.com/science/article/pii/S0167931716302283},

doi = {https://doi.org/10.1016/j.mee.2016.04.026},

issn = {0167-9317},

year  = {2016},

date = {2016-01-01},

journal = {Microelectronic Engineering},

volume = {162},

pages = {110-113},

abstract = {Double perovskites are promising materials for multiple applications on microelectronics, specially on magnetic devices development. Perhaps the most interesting one is the double perovskite Sr2FeMoO6 since its magnetic properties differ from that of other related simple perovskites: SrFeO3 and SrMoO3. In this work the evolution of the electronic properties and the magnetic moment distribution as a function of the Fe/Mo ratio in bulk and a thin slab of Sr2FeMoO6 was studied. The thin slab was constructed keeping free surfaces parallel to the (001) crystalline planes with different thickness and compositions. All calculations were made in the Density Functional Theory scheme in the Generalized Gradient Approximation, using the Perdew-Burke-Ernzerhof functional, as implemented in the DMol3 code. After being geometry optimized, the electronic Density of States and band structure were calculated, as well as the magnetic moment distribution, for each modeled system. Essential results are as follows: for the bulk cases it was found that half-metallic behavior which characterizes the stoichiometric double perovskite changes if the compound becomes molybdenum or iron rich; for the slab is remarkable the induction of magnetic moments, owed to the corresponding to iron atoms, over their neighbor atoms.},

keywords = {Density Functional Theory, electronic properties, Magnetic properties, Perovskites, Thin slabs},

pubstate = {published},

tppubtype = {article}

}

@article{ESCAMILLA2016350,

title = {First-principles study of the structural, elastic, vibrational, thermodynamic and electronic properties of the Mo2B intermetallic under pressure},

author = {R. Escamilla and E. Carvajal and M. Cruz-Irisson and M. Romero and R. G\'{o}mez and V. Marquina and D. H. Galv\'{a}n and A. Dur\'{a}n},

url = {https://www.sciencedirect.com/science/article/pii/S0022286016306755},

doi = {https://doi.org/10.1016/j.molstruc.2016.07.004},

issn = {0022-2860},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {Journal of Molecular Structure},

volume = {1125},

pages = {350-357},

abstract = {The structural, elastic, vibrational, thermodynamic and electronic properties of the Mo2B intermetallic under pressure are assessed using first-principles calculations based on the generalized gradient approximation (GGA) proposed by Perdew-Wang (PW91). Our results show that the calculated structural parameters at a pressure of zero GPa are in good agreement with the available experimental data. The effect of high pressures on the lattice constants shows that the compression along the c-axis and along the a-axis are similar. The elastic constants were calculated using the static finite strain technique, and the bulk shear moduli are derived from the ideal polycrystalline aggregate. We find that the elastic constants, elastic modulus and hardness monotonically increase as a function of pressure; consequently, the structure is dynamically stable and tends from brittle to ductile behavior under pressure. The Debye temperature θD increases and the so-called Gru¨ neisen constant γ decreases due to stiffening of the crystal structure. The phonon dispersion curves were obtained using the direct method. Additionally, the internal energy (ΔE), the Helmholtz free energy (ΔF), the entropy (S) and the lattice contribution to the heat capacity Cv were calculated and analyzed with the help of the phonon dispersion curves. The N(EF) and the electron transfer between the B and Mo atoms increase as a function of pressure.},

keywords = {Dimolybdenum boride, Electron density of states, High pressure, Phonons},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1142/S0219749916500210,

title = {Steganography on quantum pixel images using Shannon entropy},

author = {Carlos Ortega Laurel and Shi-Hai Dong and M. Cruz-Irisson},

url = {https://doi.org/10.1142/S0219749916500210},

doi = {10.1142/S0219749916500210},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {International Journal of Quantum Information},

volume = {14},

number = {05},

pages = {1650021},

abstract = {This paper presents a steganographical algorithm based on least significant bit (LSB) from the most significant bit information (MSBI) and the equivalence of a bit pixel image to a quantum pixel image, which permits to make the information communicate secretly onto quantum pixel images for its secure transmission through insecure channels. This algorithm offers higher security since it exploits the Shannon entropy for an image.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{SALAZAR20166,

title = {Effects of surface passivation by lithium on the mechanical and electronic properties of silicon nanowires},

author = {F. Salazar and L. A. P\'{e}rez and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S003810981630206X},

doi = {https://doi.org/10.1016/j.ssc.2016.08.012},

issn = {0038-1098},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {Solid State Communications},

volume = {247},

pages = {6-11},

abstract = {In this work, we present a density functional theory study of the mechanical and electronic properties of silicon nanowires (SiNWs) grown along the [111] crystallographic direction with a diamond structure and surface passivated with hydrogen (H) and lithium (Li) atoms. The study is performed within the local density approximation by applying the supercell method. The results indicate that the energy gap is a function of the Li concentration and the nanowire diameter. Furthermore, the Young\'s modulus (Y) increases as the nanowire diameter increases, consistent with experimental reports. The increase in the Li concentration at the surface leads to a larger Y value compared to the Y value of the completely H-passivated SiNWs, except for the thinner nanowires. Moreover, the structure of the latter nanowires experiences important changes when the Li concentration increases up to the maximum Li atoms per cell. These results demonstrate that it is possible to simultaneously control the energy gap and the Young’s modulus by tuning the Li concentration on the surface of the SiNWs and could help to understand the structural changes that the silicon nanowire arrays experience during the lithiation process in Li batteries.},

keywords = {electronic band structure, Impurities in semiconductors, Mechanical properties, Semiconductors},

pubstate = {published},

tppubtype = {article}

}

@article{Pilo14072016,

title = {Electronic and magnetic properties of an iron perovskite slab},

author = {J. Pilo and J. L. Rosas and E. Carvajal and M. Cruz-Irisson and},

url = {https://doi.org/10.1080/00150193.2016.1165027},

doi = {10.1080/00150193.2016.1165027},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {Ferroelectrics},

volume = {499},

number = {1},

pages = {130\textendash134},

publisher = {Taylor \& Francis},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{7556381,

title = {Perovskite-Type Thin Slabs: A First-Principles Study of Their Magnetic and Electronic Properties},

author = {Jorge Pilo and \'{A}lvaro Miranda and Eliel Carvajal and Miguel Cruz-Irisson},

doi = {10.1109/LMAG.2016.2604216},

year  = {2016},

date = {2016-01-01},

urldate = {2016-01-01},

journal = {IEEE Magnetics Letters},

volume = {7},

pages = {1-3},

keywords = {Slabs;Magnetic moments;Magnetic tunneling;Magnetic properties;Iron;Magnetic separation;Nanomagnetics;perovskites;half-metals;density functional theory;Sr-Fe-Mo-O},

pubstate = {published},

tppubtype = {article}

}

@article{Laurel_2015,

title = {Equivalence of a Bit Pixel Image to a Quantum Pixel Image*},

author = {Carlos Ortega Laurel and Shi-Hai Dong and M. Cruz-Irisson},

url = {https://dx.doi.org/10.1088/0253-6102/64/5/501},

doi = {10.1088/0253-6102/64/5/501},

year  = {2015},

date = {2015-11-01},

urldate = {2015-11-01},

journal = {Communications in Theoretical Physics},

volume = {64},

number = {5},

pages = {501},

publisher = {Chinese Physical Society and IOP Publishing},

abstract = {We propose a new method to transform a pixel image to the corresponding quantum-pixel using a qubit per pixel to represent each pixels classical weight in a quantum image matrix weight. All qubits are linear superposition, changing the coefficients level by level to the entire longitude of the gray scale with respect to the base states of the qubit. Classically, these states are just bytes represented in a binary matrix, having code combinations of 1 or 0 at all pixel locations. This method introduces a qubit-pixel image representation of images captured by classical optoelectronic methods.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1504/IJNT.2015.067212,

title = {Electronic structure and optical vibrational modes of 3C\textendashSiC nanowires},

author = {Alejandro Trejo and Miguel Ojeda and Jos\'{e} Luis Cuevas and \'{A}lvaro Miranda and Luis A. P\'{e}rez and Miguel Cruz\textendashIrisson},

url = {https://www.inderscienceonline.com/doi/abs/10.1504/IJNT.2015.067212},

doi = {10.1504/IJNT.2015.067212},

year  = {2015},

date = {2015-01-01},

journal = {International Journal of Nanotechnology},

volume = {12},

number = {3-4},

pages = {275-284},

abstract = {The electronic structure and vibrational optical modes of silicon carbide nanowires (SiCNWs) were studied using the first principles density functional theory. The nanowires were modelled along the [111] direction using the supercell technique passivating all the surface dangling bonds with H atoms, OH radicals and a combination of both. Results show that the full OH passivation lowers the band gap energy compared to the full H passivation owing to C\textendashOH surface states. A shift of the highest optical vibrational modes of Si and C to lower frequency values compared to their bulk counterparts was observed in accordance with phonon confinement scheme.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PILO20151035,

title = {Electronic Properties and Magnetic Moment Distribution on Perovskite Type Slabs: Sr2FeMoO6, SrFeO3 and SrMoO3},

author = {J. Pilo and J. L. Rosas and E. Carvajal and M. Cruz-Irisson and O. Navarro},

url = {https://www.sciencedirect.com/science/article/pii/S1875389215018118},

doi = {https://doi.org/10.1016/j.phpro.2015.12.172},

issn = {1875-3892},

year  = {2015},

date = {2015-01-01},

urldate = {2015-01-01},

journal = {Physics Procedia},

volume = {75},

pages = {1035-1040},

abstract = {Perovskite type slabs were excised from the Sr2FeMoO6, SrFeO3 and SrMoO3 bulk double perovskites, respectively, leaving (001) free surfaces. Supercells were built up for each slab, keeping a 10r{A} initial free space, to optimize the geometry. Once the minimum energy state was identified, the electronic and magnetic properties of the [001] oriented slabs have been calculated within the Density Functional Theory (DFT) scheme, with the Hubbard-corrected Local Density Approximation (LDA+U) and the CA−PZ functional. Magnetic moment for each atom in the systems was calculated; spin values for the Mo atoms are \textendash0.02{h}, − 0.13{h} and 0.56{h} for the SrMoO3 slab system case and they are aligned antiferromagnetically. Contrarily, Mo magnetic moments in the Sr2FeMoO3 slab system align antiferromagnetically to the corresponding Fe atoms, being around 10% in magnitude; meanwhile, Fe moments increase and align ferromagnetically in SrFeO3. The Densities of States (DOS) and band structures were calculated also to study the electronic behaviors. The vacuum region changes from the initial 10r{A}, as geometry stabilizes for all the slab cases; however, slab images separation evolves notoriously different for each model.},

note = {20th International Conference on Magnetism, ICM 2015},

keywords = {density of states, magnetic moment, Perovskite type slab},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1504/IJNT.2015.067207,

title = {Controlling stability and electronic properties of small\textendashdiameter SiC nanowires by fluorination},

author = {\'{A}?lvaro Miranda and Miguel Cruz\textendashIrisson and Luis A. P\'{e}rez},

url = {https://www.inderscienceonline.com/doi/abs/10.1504/IJNT.2015.067207},

doi = {10.1504/IJNT.2015.067207},

year  = {2015},

date = {2015-01-01},

urldate = {2015-01-01},

journal = {International Journal of Nanotechnology},

volume = {12},

number = {3-4},

pages = {218-225},

abstract = {We report results of a density functional theory study of the electronic properties and stability of fluorine\textendashsaturated 0.355nm\textendashthick silicon carbide nanowires with a 3C\textendashSiC core and grown along the [111] direction. The electronic band gaps of the fully fluorinated SiC nanowires are lower than that of the corresponding fully hydrogenated ones by up to 1.09 eV. Moreover, the structural stability is found to increase linearly with fluorine surface covering. For mixed fluorination and hydrogenation surface decoration schemes, the band gaps usually lie between the values of the fully fluorinated and the corresponding fully hydrogenated nanowire. Furthermore, the band gap type changes from direct to indirect for fluorine coverings exceeding 16.66%. These results indicate that fluorination of the nanowire surface may be used to control the stability as well as the size and nature of the band gap.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Calvino2014,

title = {DFT Study of the Electronic Structure of Cubic-SiC Nanopores with a C-Terminated Surface},

author = {Marbella Calvino and Alejandro Trejo and Mar\'{i}a Isabel Iturrios and Margarita Clarisaila Cris\'{o}stomo and Eliel Carvajal and M Cruz-Irisson},

url = {https://doi.org/10.1155/2014/471351},

doi = {10.1155/2014/471351},

issn = {1687-4110},

year  = {2014},

date = {2014-06-01},

journal = {Journal of Nanomaterials},

volume = {2014},

pages = {471351},

publisher = {Hindawi Publishing Corporation},

abstract = {A study of the dependence of the electronic structure and energetic stability on the chemical surface passivation of cubic porous silicon carbide (pSiC) was performed using density functional theory (DFT) and the supercell technique. The pores were modeled by removing atoms in the [001] direction to produce a surface chemistry composed of only carbon atoms (C-phase). Changes in the electronic states of the porous structures were studied by using different passivation schemes: one with hydrogen (H) atoms and the others gradually replacing pairs of H atoms with oxygen (O) atoms, fluorine (F) atoms, and hydroxide (OH) radicals. The results indicate that the band gap behavior of the C-phase pSiC depends on the number of passivation agents (other than H) per supercell. The band gap decreased with an increasing number of F, O, or OH radical groups. Furthermore, the influence of the passivation of the pSiC on its surface relaxation and the differences in such parameters as bond lengths, bond angles, and cell volume are compared between all surfaces. The results indicate the possibility of nanostructure band gap engineering based on SiC via surface passivation agents.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{TREJO201414,

title = {Theoretical approach to the phonon modes and specific heat of germanium nanowires},

author = {A. Trejo and L. L\'{o}pez-Palacios and R. V\'{a}zquez-Medina and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0921452614003706},

doi = {https://doi.org/10.1016/j.physb.2014.05.005},

issn = {0921-4526},

year  = {2014},

date = {2014-01-01},

journal = {Physica B: Condensed Matter},

volume = {453},

pages = {14-18},

abstract = {The phonon modes and specific heat of Ge nanowires were computed using a first principles density functional theory scheme with a generalized gradient approximation and finite-displacement supercell algorithms. The nanowires were modeled in three different directions: [001], [111], and [110], using the supercell technique. All surface dangling bonds were saturated with Hydrogen atoms. The results show that the specific heat of the GeNWs at room temperature increases as the nanowire diameter decreases, regardless the orientation due to the phonon confinement and surface passivation. Also the phonon confinement effects could be observed since the highest optical phonon modes in the Ge vibration interval shifted to a lower frequency compared to their bulk counterparts.},

note = {Low-Dimensional Semiconductor Structures - A part of the XXII International Material Research Congress (IMRC 2013)},

keywords = {Germanium, Nanowires, Phonons, Specific Heat},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1063/1.4878289,

title = {Electronic states of lithium passivated germanium nanowires: An ab-initio study},

author = {A Trejo and E. Carvajal and R. V\'{a}zquez-Medina and M. Cruz-Irisson},

url = {https://aip.scitation.org/doi/abs/10.1063/1.4878289},

doi = {10.1063/1.4878289},

year  = {2014},

date = {2014-01-01},

journal = {AIP Conference Proceedings},

volume = {1598},

number = {1},

pages = {114-117},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{10.1063/1.4878269,

title = {On the bonding nature of electron states for the Fe-Mo double perovskite},

author = {E. Carvajal and R. Oviedo-Roa and M. Cruz-Irisson and O. Navarro},

url = {https://doi.org/10.1063/1.4878269},

doi = {10.1063/1.4878269},

issn = {0094-243X},

year  = {2014},

date = {2014-01-01},

urldate = {2014-01-01},

journal = {AIP Conference Proceedings},

volume = {1598},

number = {1},

pages = {18-21},

abstract = {The electronic transport as well as the effect of an external magnetic field has been investigated on manganese-based materials, spinels and perovskites. Potential applications of double perovskites go from magnetic sensors to electrodes in solid-oxide fuel cells; besides the practical interests, it is known that small changes in composition modify radically the physical properties of double perovskites. We have studied the Sr2FeMoO6 double perovskite compound (SFMO) using first-principles density functional theory. The calculations were done within the generalized gradient approximation (GGA) scheme with the Perdew-Burke-Ernzerhof (PBE) functional. We have made a detailed analysis of each electronic state and the charge density maps around the Fermi level. For the electronic properties of SFMO it was used a primitive cell, for which we found the characteristic half-metallic behavior density of states composed by eg and t2g electrons from Fe and Mo atoms. Those peaks were tagged as bonding or antibonding around the Fermi level at both, valence and conduction bands.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{10.1063/1.4878310,

title = {Digital noise generators using one-dimensional chaotic maps},

author = {J. A Mart\'{i}nez-\~{N}onthe and L. Palacios-Luengas and M. Cruz-Irisson and J. A. D\'{i}az M\'{e}ndez and R. Vazquez Medina},

url = {https://doi.org/10.1063/1.4878310},

doi = {10.1063/1.4878310},

issn = {0094-243X},

year  = {2014},

date = {2014-01-01},

urldate = {2014-01-01},

journal = {AIP Conference Proceedings},

volume = {1598},

number = {1},

pages = {210-213},

abstract = {This work shows how to improve the statistical distribution of signals produced by digital noise generators designed with one-dimensional (1-D) chaotic maps. It also shows that in a digital electronic design the piecewise linear chaotic maps (PWLCM) should be considered because they do not have stability islands in its chaotic behavior region, as it occurs in the case of the logistic map, which is commonly used to build noise generators. The design and implementation problems of the digital noise generators are analyzed and a solution is proposed. This solution relates the output of PWLCM, usually defined in the real numbers\' domain, with a codebook of S elements, previously defined. The proposed solution scheme produces digital noise signals with a statistical distribution close to a uniform distribution. Finally, this work shows that it is possible to have control over the statistical distribution of the noise signal by selecting the control parameter of the PWLCM and using, as a design criterion, the bifurcation diagram.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PILO2014103,

title = {Interactions among magnetic moments in the double perovskites Sr2Fe1+xMo1−xO6},

author = {J. Pilo and E. Carvajal and R. Oviedo-Roa and M. Cruz-Irisson and O. Navarro},

url = {https://www.sciencedirect.com/science/article/pii/S0921452614006000},

doi = {https://doi.org/10.1016/j.physb.2014.07.057},

issn = {0921-4526},

year  = {2014},

date = {2014-01-01},

urldate = {2014-01-01},

journal = {Physica B: Condensed Matter},

volume = {455},

pages = {103-105},

abstract = {It is well known that every double perovskite shows a characteristic magnetic behavior, as a consequence of the interactions among the magnetic moments associated with the atoms in their cells; at the same time, the electric and magnetic properties of the bulk double perovskite Sr2FeMoO6 are well characterized. In this work we studied the iron rich compounds Sr2Fe1+xMo1−xO6, using a supercell to model such concentrations that made Fe richer perovskites by ±66.6% and ±200%. Starting from the stoichiometric double perovskite, and modifying the Fe/Mo ratio in the compound, the study of these materials were based on the calculation of the magnetic moment at each atom, as well as the partial density of states.},

note = {21st Latin American Symposium on Solid State Physics - SLAFES 2013},

keywords = {Density Functional Theory, Double perovskites, Magnetic moments},

pubstate = {published},

tppubtype = {article}

}

@article{Trejo2013,

title = {Ab-initio study of anisotropic and chemical surface modifications of $beta$-SiC nanowires},

author = {Alejandro Trejo and Jos\'{e} Luis Cuevas and Fernando Salazar and Eliel Carvajal and Miguel Cruz-Irisson},

url = {https://doi.org/10.1007/s00894-012-1605-y},

doi = {10.1007/s00894-012-1605-y},

issn = {0948-5023},

year  = {2013},

date = {2013-05-01},

journal = {Journal of Molecular Modeling},

volume = {19},

number = {5},

pages = {2043-2048},

abstract = {The electronic band structure and electronic density of states of cubic SiC nanowires (SiCNWs) in the directions [001], [111], and [112] were studied by means of Density Functional Theory (DFT) based on the generalized gradient approximation and the supercell technique. The surface dangling bonds were passivated using hydrogen (H) atoms and OH radicals in order to study the effects of this passivation on the electronic states of the SiCNWs. The calculations show a clear dependence of the electronic properties of the SiCNWs on the quantum confinement, orientation, and chemical passivation of the surface. In general, surface passivation with either H or OH radicals removes the dangling bond states from the band gap, and OH saturation appears to produce a smaller band gap than H passivation. An analysis of the atom-resolved density of states showed that there is substantial charge transfer between the Si and O atoms in the OH-terminated case, which reduces the band gap compared to the H-terminated case, in which charge transfer mainly occurs between the Si and C atoms.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{TREJO201310,

title = {Anisotropic effects on the radial breathing mode of silicon nanowires: An ab initio study},

author = {A. Trejo and R. Vazquez-Medina and G. I. Duchen and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S1386947713000404},

doi = {https://doi.org/10.1016/j.physe.2013.02.006},

issn = {1386-9477},

year  = {2013},

date = {2013-01-01},

journal = {Physica E: Low-dimensional Systems and Nanostructures},

volume = {51},

pages = {10-14},

abstract = {The effect of orientation on the frequency of the radial breathing mode (RBM) of silicon nanowires (SiNWs) is investigated by means of the first principles Density Functional Theory approach through the generalized gradient approximation. We compare the RBM frequency of SiNWs orientated in three different directions, [001], [111], and [110]. The RBM is observed by the calculation of the phonon band structure and density of states of the SiNWs through the supercell finite displacement method. Results show that the SiNWs are stable in the three chosen directions since there are no negative frequencies in their phonon band structure and density of states. A clear dependence of the RBM frequency with respect to the growth direction of the nanowires and the phonon confinement was observed as the RBM frequency decreased with an inverse power law in each nanowire direction, with the fitting parameters dependent on the growth direction. These results are important since they could be used as a fingerprint to identify them within different spectroscopy techniques such as Raman.},

note = {IMRC 2012},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{molecules18044776,

title = {Computational Modeling of the Size Effects on the Optical Vibrational Modes of H-Terminated Ge Nanostructures},

author = {Alejandro Trejo and Miguel Cruz-Irisson},

url = {https://www.mdpi.com/1420-3049/18/4/4776},

doi = {10.3390/molecules18044776},

issn = {1420-3049},

year  = {2013},

date = {2013-01-01},

journal = {Molecules},

volume = {18},

number = {4},

pages = {4776--4785},

abstract = {The vibrational dispersion relations of porous germanium (pGe) and germanium nanowires (GeNWs) were calculated using the ab initio density functional perturbation theory with a generalized gradient approximation with norm-conserving pseudopotentials. Both pores and nanowires were modeled using the supercell technique. All of the surface dangling bonds were saturated with hydrogen atoms. To address the difference in the confinement between the pores and the nanowires, we calculated the vibrational density of states of the two materials. The results indicate that there is a slight shift in the highest optical mode of the Ge-Ge vibration interval in all of the nanostructures due to the phonon confinement effects. The GeNWs exhibit a reduced phonon confinement compared with the porous Ge due to the mixed Ge-dihydride vibrational modes around the maximum bulk Ge optical mode of approximately 300 cm−1; however, the general effects of such confinements could still be noticed, such as the shift to lower frequencies of the highest optical mode belonging to the Ge vibrations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PALACIOSLUENGAS2013264,

title = {Digital noise produced by a non discretized tent chaotic map},

author = {L. Palacios-Luengas and G. Delgado-Guti\'{e}rrez and M. Cruz-Irisson and J. L. Del-Rio-Correa and R. V\'{a}zquez-Medina},

url = {https://www.sciencedirect.com/science/article/pii/S0167931713003560},

doi = {https://doi.org/10.1016/j.mee.2013.03.127},

issn = {0167-9317},

year  = {2013},

date = {2013-01-01},

urldate = {2013-01-01},

journal = {Microelectronic Engineering},

volume = {112},

pages = {264-268},

abstract = {This paper shows a digital electronic system that produces uniformly distributed binary sequences using the inverted tent chaotic map (ITCM) without the scaling and discretization processes. The proposed system has been developed considering a numerical representation of floating point with a 64-bit precision format according to the standard IEEE-754. The proposed system has four important advantages: (i) the produced binary sequences are uniformly distributed and they satisfy 10 randomness tests defined in the NIST 800-22SP guide, (ii) the statistical behavior of the ITCM is not affected by the scaling and discretization processes; therefore, the chaotic map used is not modified, (iii) the statistical behavior of the ITCM does not have stability islands inside the chaotic region, although its control parameter is changed, as it occurs with the logistic chaotic map and (iv) the statistical behavior of the binary sequences is conducted by the control parameter and the skeleton of the bifurcation diagram of the ITCM, which can be considered as the security keys of the system.},

keywords = {Binary sequences uniformly distributed, Chaotic noise generator, Inverted tent chaotic map, Pseudorandom noise generator},

pubstate = {published},

tppubtype = {article}

}

@article{Trejo2012,

title = {Computational simulation of the effects of oxygen on the electronic states of hydrogenated 3C-porous SiC},

author = {Alejandro Trejo and Marbella Calvino and Estrella Ramos and Miguel Cruz-Irisson},

url = {https://doi.org/10.1186/1556-276X-7-471},

doi = {10.1186/1556-276X-7-471},

issn = {1556-276X},

year  = {2012},

date = {2012-08-22},

journal = {Nanoscale Research Letters},

volume = {7},

number = {1},

pages = {471},

abstract = {A computational study of the dependence of the electronic band structure and density of states on the chemical surface passivation of cubic porous silicon carbide (pSiC) was performed using ab initio density functional theory and the supercell method. The effects of the porosity and the surface chemistry composition on the energetic stability of pSiC were also investigated. The porous structures were modeled by removing atoms in the [001] direction to produce two different surface chemistries: one fully composed of silicon atoms and one composed of only carbon atoms. The changes in the electronic states of the porous structures as a function of the oxygen (O) content at the surface were studied. Specifically, the oxygen content was increased by replacing pairs of hydrogen (H) atoms on the pore surface with O atoms attached to the surface via either a double bond (Xthinspace=thinspaceO) or a bridge bond (X-O-X, Xthinspace=thinspaceSi or C). The calculations show that for the fully H-passivated surfaces, the forbidden energy band is larger for the C-rich phase than for the Si-rich phase. For the partially oxygenated Si-rich surfaces, the band gap behavior depends on the O bond type. The energy gap increases as the number of O atoms increases in the supercell if the O atoms are bridge-bonded, whereas the band gap energy does not exhibit a clear trend if O is double-bonded to the surface. In all cases, the gradual oxygenation decreases the band gap of the C-rich surface due to the presence of trap-like states.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Dong2012,

title = {Energy spectrum for a modified Rosen-Morse potential solved by proper quantization rule and its thermodynamic properties},

author = {Shi-Hai Dong and M. Cruz-Irisson},

url = {https://doi.org/10.1007/s10910-011-9931-3},

doi = {10.1007/s10910-011-9931-3},

issn = {1572-8897},

year  = {2012},

date = {2012-04-01},

urldate = {2012-04-01},

journal = {Journal of Mathematical Chemistry},

volume = {50},

number = {4},

pages = {881-892},

abstract = {We apply our recently proposed proper quantization rule, $$backslashint_x_A^x_Bk(x) dx -backslashint_x_0A^x_0Bk_0(x) dx=nbackslashpi$$, where $$k(x)=backslashsqrt2 M [E-V(x) ]/backslashhbar$$to obtain the energy spectrum of the modified Rosen-Morse potential. The beauty and symmetry of this proper rule come from its meaning\textemdashwhenever the number of the nodes of $$backslashphi(x)$$or the number of the nodes of the wave function ψ(x) increases by one, the momentum integral $$backslashint_x_A^x_B k(x)dx$$will increase by π. Based on this new approach, we present a vibrational high temperature partition function in order to study thermodynamic functions such as the vibrational mean energy U, specific heat C, free energy F and entropy S. It is surprising to note that the specific heat C (k = 1) first increases with β and arrives to the maximum value and then decreases with it. However, it is shown that the entropy S (k = 1) first increases with the deepness of potential well λ and then decreases with it.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{CALVINO20121482,

title = {A Density Functional Theory study of the chemical surface modification of β-SiC nanopores},

author = {M. Calvino and A. Trejo and J. L. Cuevas and E. Carvajal and G. I. Duch\'{e}n and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0921510712000918},

doi = {https://doi.org/10.1016/j.mseb.2012.02.009},

issn = {0921-5107},

year  = {2012},

date = {2012-01-01},

journal = {Materials Science and Engineering: B},

volume = {177},

number = {16},

pages = {1482-1486},

abstract = {The dependence of the electronic band structure and density of states on the chemical surface passivation of cubic porous silicon carbide (PSiC) is investigated by means of the ab-initio Density Functional Theory and the supercell method in which pores with different sizes and morphologies were created. The porous structures were modeled by removing atoms in the [001] direction producing two different surface chemistries; one with both Silicon (Si) and Carbon (C) atoms and the other with only Si or C atoms. The changes in the electronic band gap due to a Si-rich and C-rich phase in the porous surfaces are studied with two kind of surface passivation, one with hydrogen atoms and other with a combination between hydrogen and oxygen atoms. The calculations show that for the hydrogenated case, the band gap is larger for the C-rich than for the Si-rich case. For the partial oxygenation the tendency is contrary, by decreasing and increasing the band gap for the C-rich and Si-rich configuration, respectively, according to the percentage of oxygen in the pore surface.},

note = {Advances in Semiconducting Materials},

keywords = {Density Functional Theory, Porous silicon carbide, Surface passivation},

pubstate = {published},

tppubtype = {article}

}

@article{CUEVAS20128360,

title = {Ab-initio modeling of oxygen on the surface passivation of 3CSiC nanostructures},

author = {J. L. Cuevas and A. Trejo and M. Calvino and E. Carvajal and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0169433212006289},

doi = {https://doi.org/10.1016/j.apsusc.2012.03.175},

issn = {0169-4332},

year  = {2012},

date = {2012-01-01},

journal = {Applied Surface Science},

volume = {258},

number = {21},

pages = {8360-8365},

abstract = {In this work the effect of OH on the electronic states of H-passivated 3CSiC nanostructures, was studied by means of Density Functional Theory. We compare the electronic band structure for a [111]-oriented nanowire with total H, OH passivation and a combination of both. Also the electronic states of a porous silicon carbide case (PSiC) a C-rich pore surface in which the dangling bonds on the surface are saturated with H and OH was studied. The calculations show that the surface replacement of H with OH radicals is always energetically favorable and more stable. In all cases the OH passivation produced a similar effect than the H passivation, with electronic band gap of lower energy value than the H-terminated phase. When the OH groups are attached to C atoms, the band gap feature is changed from direct to indirect. The results indicate the possibility of band gap engineering on SiC nanostructures through the surface passivation species.},

note = {VII International Workshop on Semiconductor Surface Passivation, KRAK\'{O}W, POLAND, September 11 - 15, 2011},

keywords = {Density Functional Theory, Nanowires, Porous semiconductors, Silicon carbide},

pubstate = {published},

tppubtype = {article}

}

@article{MIRANDA20121230,

title = {Interconnection effects on the electronic and optical properties of Ge nanostructures: A semi-empirical approach},

author = {A. Miranda and A. Trejo and E. Canadell and R. Rurali and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S1386947712000318},

doi = {https://doi.org/10.1016/j.physe.2012.01.017},

issn = {1386-9477},

year  = {2012},

date = {2012-01-01},

journal = {Physica E: Low-dimensional Systems and Nanostructures},

volume = {44},

number = {7},

pages = {1230-1235},

abstract = {A supercell model is applied to a semi-empirical sp3s⁎ tight-binding (TB) approach to calculate the electronic band gap and imaginary part of the dielectric function of two Ge nanostructures\textemdashordered arrays of pores and stand-alone nanowires\textemdashand one example of their interconnections. The pores are modeled by removing columns of Ge atoms in the [001] direction. The results of the variation band gap are compared with those obtained by TB-sp3, TB-sp3d5s⁎, density functional theory (DFT), and experimental data. The imaginary part of the dielectric function is calculated by including both intra-atomic and inter-atomic dipole matrices using (for both) the interconnected and free standing (chessboard-like) models for the Ge skeleton. The calculation shows that although the intra-atomic matrix elements are small in magnitude a quantitative treatment of the optical absorption spectrum of Ge nanostructures may not be possible without the inclusion of these matrix elements. Finally, the calculations confirm that also ordered porous germanium (PGe) show a clear quantum confinement signature, even though the wave functions could in principle behave like delocalized Bloch states.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{TREJO2012141,

title = {Phonon band structure of porous Ge from ab initio supercell calculation},

author = {A. Trejo and J. L. Cuevas and R. V\'{a}zquez-Medina and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S016793171100503X},

doi = {https://doi.org/10.1016/j.mee.2011.05.007},

issn = {0167-9317},

year  = {2012},

date = {2012-01-01},

journal = {Microelectronic Engineering},

volume = {90},

pages = {141-144},

abstract = {The phonon band structures for porous Ge (PGe) are performed by means of full ab initio calculations. The supercell technique is used and ordered pores are produced by removing columns of Ge atoms from their crystalline structures. The nanostructures are fully relaxed in order to obtain the minimum energy and avoid negative frequencies derived from instabilities of the system. The phonon dispersion and phonon density of states were studied using the Density Functional Theory through the finite displacement algorithm. The results show for the dehydrogenated PGe case a notable shift of the highest optical mode towards lower frequencies with respect to the bulk crystalline Ge. This fact is in agreement with the experimental data such as Raman scattering.},

note = {Micro\&Nano 2010},

keywords = {Density Functional Theory, Phonons, porous germanium, Supercell approach},

pubstate = {published},

tppubtype = {article}

}

@article{TREJO201292,

title = {Phonon optical modes and electronic properties in diamond nanowires},

author = {A. Trejo and A. Miranda and L. Ni\~{n}o Rivera and A. D\'{i}az-M\'{e}ndez and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S016793171100476X},

doi = {https://doi.org/10.1016/j.mee.2011.04.052},

issn = {0167-9317},

year  = {2012},

date = {2012-01-01},

journal = {Microelectronic Engineering},

volume = {90},

pages = {92-95},

abstract = {A local bond-polarization model based on the displacement\textendashdisplacement Green’s function and the Born potential are applied to study the confined optical phonons and Raman scattering of diamond nanowires (DNWs). Also, the electronic band structure of DNWs are investigated by means of a semi-empirical tight-binding approach and compared with density functional theory within local density approximation. The supercell technique is applied to model DNWs along [001] direction preserving the crystalline diamond atomic structure. The results of both phonons and electrons show a clear quantum confinement signature. Moreover, the highest energy Raman peak shows a shift towards low frequencies respect to the bulk crystalline diamond, in agreement with experimental data.},

note = {Micro\&Nano 2010},

keywords = {Diamond, Nanowires, Phonons, Raman scattering, Tight-binding},

pubstate = {published},

tppubtype = {article}

}

@article{CARVAJAL20121514,

title = {FeMo double perovskite: From small clusters to bulk material},

author = {E. Carvajal and R. Oviedo-Roa and M. Cruz-Irisson and O. Navarro},

url = {https://www.sciencedirect.com/science/article/pii/S0921510712002048},

doi = {https://doi.org/10.1016/j.mseb.2012.03.041},

issn = {0921-5107},

year  = {2012},

date = {2012-01-01},

urldate = {2012-01-01},

journal = {Materials Science and Engineering: B},

volume = {177},

number = {16},

pages = {1514-1517},

abstract = {To understand the differences in behaviour between up- and down-spin electrons observed in the half-metallic Sr2FeMoO6 double perovskite, the density of states (DOS) was studied for the (FeO6)−4 and (MoO6)−6 octahedral clusters using first-principles density functional theory within the generalised gradient approximation (GGA) scheme and the Perdew\textendashBurke\textendashErnzerhof (PBE) functional. Our results reveal that half-metallic character is present, even starting from an isolated (FeO6)−4 cluster, and is a consequence of spin decoupling of antibonding hybridisations between iron t2g states and oxygen p states (t2ga states), i.e., t2ga states lie below the Highest Occupied Molecular Orbital (HOMO) in the up-spin channel, whereas they lie above the HOMO level in the down-spin channel. The spin-induced shifting between up-spin and down-spin DOS situates the HOMO in such a way that the molecular orbitals oxygen p states (p bands) are fully spin-paired by octet electrons. Thus, the down-spin channel has metallic character because the HOMO lies just at the p bands, and the up-spin channel is semiconducting because the HOMO falls within the energy gap between the t2ga and ega bands. Finally, the (MoO6)−6 octahedron does not inhibit the perovskite half-metallic character since this cluster has a zero total spin.},

note = {Advances in Semiconducting Materials},

keywords = {Bulk material, Density Functional Theory, Double perovskites, Half-metallic ferromagnetism, Small clusters},

pubstate = {published},

tppubtype = {article}

}

@article{LOPEZHERNANDEZ2012163,

title = {A current mode CMOS noise generator using multiple Bernoulli maps},

author = {J. L\'{o}pez-Hern\'{a}ndez and A. D\'{i}az-M\'{e}ndez and J. L. Del-R\'{i}o-Correa and M. Cruz-Irisson and R. V\'{a}zquez-Medina},

url = {https://www.sciencedirect.com/science/article/pii/S0167931711005053},

doi = {https://doi.org/10.1016/j.mee.2011.05.009},

issn = {0167-9317},

year  = {2012},

date = {2012-01-01},

urldate = {2012-01-01},

journal = {Microelectronic Engineering},

volume = {90},

pages = {163-167},

abstract = {This paper presents the analysis and design of a chaotic noise generator using statistical mechanic tools. The noise generator is a CMOS analog circuit operating in current mode, which generates chaotic signals using four Bernoulli chaotic maps with topological dependency on each other. They are randomly or deterministically selected to be applied by iterating an initial condition. These variants of the Bernoulli map are different in their slope and attenuation process. The initial condition can be considered as the secret key in the generation of chaotic noise. The advantage of this chaotic noise generator is that its’ control parameter can be selected within an interval greater than the one obtained when basic Bernoulli map is used.},

note = {Micro\&Nano 2010},

keywords = {Chaotic noise, CMOS circuits, Noise generators},

pubstate = {published},

tppubtype = {article}

}

@article{MARTINEZNONTHE2012168,

title = {Chaotic block cryptosystem using high precision approaches to tent map},

author = {J. A. Mart\'{i}nez-\~{N}onthe and A. Casta\~{n}eda-Sol\'{i}s and A. D\'{i}az-M\'{e}ndez and M. Cruz-Irisson and R. V\'{a}zquez-Medina},

url = {https://www.sciencedirect.com/science/article/pii/S0167931711004254},

doi = {https://doi.org/10.1016/j.mee.2011.04.005},

issn = {0167-9317},

year  = {2012},

date = {2012-01-01},

urldate = {2012-01-01},

journal = {Microelectronic Engineering},

volume = {90},

pages = {168-172},

abstract = {This paper presents the implementation and evaluation of a block cryptosystem based in chaotic maps. The noise function used in this cryptosystem is an approximation to the chaotic tent map, and for this reason, it is named pseudo chaotic tent map (PCT map). PCT map has been analyzed and evaluated using the statistical mechanic tools such as: bifurcation diagram, Lyapunov exponent and invariant distribution. In order to determine the influence of PCT map in the syntactic, semantic and statistic of a message, this map has been used on the non-balanced and dynamic network proposed by Kocarev. Cryptosystem has been evaluated using concepts of the information theory, such as: entropy and mutual information. The randomness of the produced cryptograms has been evaluated using the statistical tests suite of NIST.},

note = {Micro\&Nano 2010},

keywords = {Block cryptosystem, Chaotic cryptosystem, Chaotic maps},

pubstate = {published},

tppubtype = {article}

}