The Experts below are selected from a list of 30549 Experts worldwide ranked by ideXlab platform
C.a. Duque - One of the best experts on this subject based on the ideXlab platform.
-
donor impurity related linear and nonlinear optical absorption coefficients in gaas ga1 xalxas concentric double quantum rings effects of geometry hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2014Co-Authors: H.m. Baghramyan, M G Barseghyan, A A Kirakosyan, Ricardo Restrepo, M E Moraramos, C.a. DuqueAbstract:Abstract The linear and nonlinear optical absorption associated with the transition between 1s and 2s states corresponding to the electron-donor-impurity complex in GaAs / Ga 1 − x Al x As three-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and the variation of the Aluminum Concentration, the energies of the ground and first excited s-like states of a donor impurity in such a system have been calculated using the effective mass approximation and a variational method. The energies of these states and the corresponding threshold energy of the optical transitions are examined as functions of hydrostatic pressure, Aluminum Concentration, radial impurity position, as well as the geometrical dimensions of the structure. The dependencies of the linear, nonlinear and total optical absorption coefficients as functions of the incident photon energy are investigated for different values of those mentioned parameters. It is found that the influences mentioned above lead to either redshifts or blueshifts of the resonant peaks of the optical absorption spectrum. It is particularly discussed the unusual property exhibited by the third-order nonlinear of becoming positive for photon energies below the resonant transition one. It is shown that this phenomenon is associated with the particular features of the system under study, which determine the values of the electric dipole moment matrix elements.
-
Donor impurity-related linear and nonlinear optical absorption coefficients in GaAs/Ga1−xAlxAs concentric double quantum rings: Effects of geometry, hydrostatic pressure, and Aluminum Concentration
Journal of Luminescence, 2014Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, Ricardo Restrepo, M.e. Mora-ramos, C.a. DuqueAbstract:Abstract The linear and nonlinear optical absorption associated with the transition between 1s and 2s states corresponding to the electron-donor-impurity complex in GaAs / Ga 1 − x Al x As three-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and the variation of the Aluminum Concentration, the energies of the ground and first excited s-like states of a donor impurity in such a system have been calculated using the effective mass approximation and a variational method. The energies of these states and the corresponding threshold energy of the optical transitions are examined as functions of hydrostatic pressure, Aluminum Concentration, radial impurity position, as well as the geometrical dimensions of the structure. The dependencies of the linear, nonlinear and total optical absorption coefficients as functions of the incident photon energy are investigated for different values of those mentioned parameters. It is found that the influences mentioned above lead to either redshifts or blueshifts of the resonant peaks of the optical absorption spectrum. It is particularly discussed the unusual property exhibited by the third-order nonlinear of becoming positive for photon energies below the resonant transition one. It is shown that this phenomenon is associated with the particular features of the system under study, which determine the values of the electric dipole moment matrix elements.
-
linear and nonlinear optical absorption coefficients in gaas ga1 xalxas concentric double quantum rings effects of hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2013Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, R.l. Restrepo, C.a. DuqueAbstract:Abstract The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga1−xAlxAs two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and Aluminum Concentration the energies of the ground ( n = 1 , l = 0 ) and the first excited state ( n = 2 , l = 1 ) have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and Aluminum Concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, Aluminum Concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the Aluminum Concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum.
-
binding energy of hydrogenic donor impurity in gaas ga1 xalxas concentric double quantum rings effects of geometry hydrostatic pressure temperature and Aluminum Concentration
Physica E-low-dimensional Systems & Nanostructures, 2013Co-Authors: H.m. Baghramyan, C.a. Duque, M G Barseghyan, A A KirakosyanAbstract:Abstract We consider the effects of hydrostatic pressure, temperature, Aluminum Concentration and impurity position on hydrogen-like donor binding energy in GaAs / Ga 1 − x Al x As concentric double quantum rings. The ground state energy and the impurity wave function are calculated using the variational method. For the hydrostatic pressure effects the Γ − X crossover has been taken into account. The probability density of electron without electron-impurity interaction have been investigated for different values of the sizes of the structure. The dependencies of the binding energy on geometry of the structure, hydrostatic pressure, temperature, Aluminum Concentration and impurity positions have been also investigated. The results show that the binding energy is an increasing (decreasing) function of the hydrostatic pressure and Aluminum Concentration (temperature). Additionally we have found that when the impurity is placed within the inner ring, the binding energy behavior strongly depends on the widths of the outer ring and coupling barrier.
-
Linear and nonlinear optical absorption coefficients in GaAs/Ga1 xAlxAs concentric double quantum rings: Effects of hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2013Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, R.l. Restrepo, C.a. DuqueAbstract:Abstract The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga1−xAlxAs two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and Aluminum Concentration the energies of the ground ( n = 1 , l = 0 ) and the first excited state ( n = 2 , l = 1 ) have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and Aluminum Concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, Aluminum Concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the Aluminum Concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum.
H.m. Baghramyan - One of the best experts on this subject based on the ideXlab platform.
-
donor impurity related linear and nonlinear optical absorption coefficients in gaas ga1 xalxas concentric double quantum rings effects of geometry hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2014Co-Authors: H.m. Baghramyan, M G Barseghyan, A A Kirakosyan, Ricardo Restrepo, M E Moraramos, C.a. DuqueAbstract:Abstract The linear and nonlinear optical absorption associated with the transition between 1s and 2s states corresponding to the electron-donor-impurity complex in GaAs / Ga 1 − x Al x As three-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and the variation of the Aluminum Concentration, the energies of the ground and first excited s-like states of a donor impurity in such a system have been calculated using the effective mass approximation and a variational method. The energies of these states and the corresponding threshold energy of the optical transitions are examined as functions of hydrostatic pressure, Aluminum Concentration, radial impurity position, as well as the geometrical dimensions of the structure. The dependencies of the linear, nonlinear and total optical absorption coefficients as functions of the incident photon energy are investigated for different values of those mentioned parameters. It is found that the influences mentioned above lead to either redshifts or blueshifts of the resonant peaks of the optical absorption spectrum. It is particularly discussed the unusual property exhibited by the third-order nonlinear of becoming positive for photon energies below the resonant transition one. It is shown that this phenomenon is associated with the particular features of the system under study, which determine the values of the electric dipole moment matrix elements.
-
Donor impurity-related linear and nonlinear optical absorption coefficients in GaAs/Ga1−xAlxAs concentric double quantum rings: Effects of geometry, hydrostatic pressure, and Aluminum Concentration
Journal of Luminescence, 2014Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, Ricardo Restrepo, M.e. Mora-ramos, C.a. DuqueAbstract:Abstract The linear and nonlinear optical absorption associated with the transition between 1s and 2s states corresponding to the electron-donor-impurity complex in GaAs / Ga 1 − x Al x As three-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and the variation of the Aluminum Concentration, the energies of the ground and first excited s-like states of a donor impurity in such a system have been calculated using the effective mass approximation and a variational method. The energies of these states and the corresponding threshold energy of the optical transitions are examined as functions of hydrostatic pressure, Aluminum Concentration, radial impurity position, as well as the geometrical dimensions of the structure. The dependencies of the linear, nonlinear and total optical absorption coefficients as functions of the incident photon energy are investigated for different values of those mentioned parameters. It is found that the influences mentioned above lead to either redshifts or blueshifts of the resonant peaks of the optical absorption spectrum. It is particularly discussed the unusual property exhibited by the third-order nonlinear of becoming positive for photon energies below the resonant transition one. It is shown that this phenomenon is associated with the particular features of the system under study, which determine the values of the electric dipole moment matrix elements.
-
linear and nonlinear optical absorption coefficients in gaas ga1 xalxas concentric double quantum rings effects of hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2013Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, R.l. Restrepo, C.a. DuqueAbstract:Abstract The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga1−xAlxAs two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and Aluminum Concentration the energies of the ground ( n = 1 , l = 0 ) and the first excited state ( n = 2 , l = 1 ) have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and Aluminum Concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, Aluminum Concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the Aluminum Concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum.
-
binding energy of hydrogenic donor impurity in gaas ga1 xalxas concentric double quantum rings effects of geometry hydrostatic pressure temperature and Aluminum Concentration
Physica E-low-dimensional Systems & Nanostructures, 2013Co-Authors: H.m. Baghramyan, C.a. Duque, M G Barseghyan, A A KirakosyanAbstract:Abstract We consider the effects of hydrostatic pressure, temperature, Aluminum Concentration and impurity position on hydrogen-like donor binding energy in GaAs / Ga 1 − x Al x As concentric double quantum rings. The ground state energy and the impurity wave function are calculated using the variational method. For the hydrostatic pressure effects the Γ − X crossover has been taken into account. The probability density of electron without electron-impurity interaction have been investigated for different values of the sizes of the structure. The dependencies of the binding energy on geometry of the structure, hydrostatic pressure, temperature, Aluminum Concentration and impurity positions have been also investigated. The results show that the binding energy is an increasing (decreasing) function of the hydrostatic pressure and Aluminum Concentration (temperature). Additionally we have found that when the impurity is placed within the inner ring, the binding energy behavior strongly depends on the widths of the outer ring and coupling barrier.
-
Linear and nonlinear optical absorption coefficients in GaAs/Ga1 xAlxAs concentric double quantum rings: Effects of hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2013Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, R.l. Restrepo, C.a. DuqueAbstract:Abstract The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga1−xAlxAs two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and Aluminum Concentration the energies of the ground ( n = 1 , l = 0 ) and the first excited state ( n = 2 , l = 1 ) have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and Aluminum Concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, Aluminum Concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the Aluminum Concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum.
Albert A. Kirakosyan - One of the best experts on this subject based on the ideXlab platform.
-
Donor impurity-related linear and nonlinear optical absorption coefficients in GaAs/Ga1−xAlxAs concentric double quantum rings: Effects of geometry, hydrostatic pressure, and Aluminum Concentration
Journal of Luminescence, 2014Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, Ricardo Restrepo, M.e. Mora-ramos, C.a. DuqueAbstract:Abstract The linear and nonlinear optical absorption associated with the transition between 1s and 2s states corresponding to the electron-donor-impurity complex in GaAs / Ga 1 − x Al x As three-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and the variation of the Aluminum Concentration, the energies of the ground and first excited s-like states of a donor impurity in such a system have been calculated using the effective mass approximation and a variational method. The energies of these states and the corresponding threshold energy of the optical transitions are examined as functions of hydrostatic pressure, Aluminum Concentration, radial impurity position, as well as the geometrical dimensions of the structure. The dependencies of the linear, nonlinear and total optical absorption coefficients as functions of the incident photon energy are investigated for different values of those mentioned parameters. It is found that the influences mentioned above lead to either redshifts or blueshifts of the resonant peaks of the optical absorption spectrum. It is particularly discussed the unusual property exhibited by the third-order nonlinear of becoming positive for photon energies below the resonant transition one. It is shown that this phenomenon is associated with the particular features of the system under study, which determine the values of the electric dipole moment matrix elements.
-
linear and nonlinear optical absorption coefficients in gaas ga1 xalxas concentric double quantum rings effects of hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2013Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, R.l. Restrepo, C.a. DuqueAbstract:Abstract The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga1−xAlxAs two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and Aluminum Concentration the energies of the ground ( n = 1 , l = 0 ) and the first excited state ( n = 2 , l = 1 ) have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and Aluminum Concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, Aluminum Concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the Aluminum Concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum.
-
Linear and nonlinear optical absorption coefficients in GaAs/Ga1 xAlxAs concentric double quantum rings: Effects of hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2013Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, Albert A. Kirakosyan, R.l. Restrepo, C.a. DuqueAbstract:Abstract The linear and nonlinear intra-band optical absorption coefficients in GaAs/Ga1−xAlxAs two-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and Aluminum Concentration the energies of the ground ( n = 1 , l = 0 ) and the first excited state ( n = 2 , l = 1 ) have been found using the effective mass approximation and the transfer matrix formalism. The energies of these states and the corresponding threshold energy of the intra-band optical transitions are examined as a function of hydrostatic pressure and Aluminum Concentration for different sizes of the structure. We also investigated the dependencies of the linear, nonlinear, and total optical absorption coefficients as functions of the incident photon energy for different values of hydrostatic pressure, Aluminum Concentration, sizes of the structure, and incident optical intensity. Its is found that the effects of the hydrostatic pressure and the Aluminum Concentration lead to a shifting of the resonant peaks of the intra-band optical spectrum.
-
Binding energy of hydrogenic donor impurity in GaAs/Ga1−xAlxAs concentric double quantum rings: Effects of geometry, hydrostatic pressure, temperature, and Aluminum Concentration
Physica E: Low-dimensional Systems and Nanostructures, 2013Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, C.a. Duque, Albert A. KirakosyanAbstract:Abstract We consider the effects of hydrostatic pressure, temperature, Aluminum Concentration and impurity position on hydrogen-like donor binding energy in GaAs / Ga 1 − x Al x As concentric double quantum rings. The ground state energy and the impurity wave function are calculated using the variational method. For the hydrostatic pressure effects the Γ − X crossover has been taken into account. The probability density of electron without electron-impurity interaction have been investigated for different values of the sizes of the structure. The dependencies of the binding energy on geometry of the structure, hydrostatic pressure, temperature, Aluminum Concentration and impurity positions have been also investigated. The results show that the binding energy is an increasing (decreasing) function of the hydrostatic pressure and Aluminum Concentration (temperature). Additionally we have found that when the impurity is placed within the inner ring, the binding energy behavior strongly depends on the widths of the outer ring and coupling barrier.
-
Effects of hydrostatic pressure, temperature, electric field and Aluminum Concentration on the electronic states in GaAs/Ga1−xAlxAs concentric double quantum rings
Journal of Physics: Conference Series, 2012Co-Authors: H.m. Baghramyan, Manuk G. Barseghyan, C.a. Duque, Albert A. KirakosyanAbstract:Using the effective mass approximation and transfer matrix formalism the ground state energy of an electron in GaAs/Ga1−xAlxAs concentric double quantum rings is calculated taking into account the combined effects of electric field, hydrostatic pressure, temperature and Aluminum Concentration. The ground state energy dependences on the mentioned factors are presented for different values of the sizes of rings and electric field strength. It is found that the considered effects mainly depend on the dimensions of quantum rings.
A A Kirakosyan - One of the best experts on this subject based on the ideXlab platform.
-
donor impurity related linear and nonlinear optical absorption coefficients in gaas ga1 xalxas concentric double quantum rings effects of geometry hydrostatic pressure and Aluminum Concentration
Journal of Luminescence, 2014Co-Authors: H.m. Baghramyan, M G Barseghyan, A A Kirakosyan, Ricardo Restrepo, M E Moraramos, C.a. DuqueAbstract:Abstract The linear and nonlinear optical absorption associated with the transition between 1s and 2s states corresponding to the electron-donor-impurity complex in GaAs / Ga 1 − x Al x As three-dimensional concentric double quantum rings are investigated. Taking into account the combined effects of hydrostatic pressure and the variation of the Aluminum Concentration, the energies of the ground and first excited s-like states of a donor impurity in such a system have been calculated using the effective mass approximation and a variational method. The energies of these states and the corresponding threshold energy of the optical transitions are examined as functions of hydrostatic pressure, Aluminum Concentration, radial impurity position, as well as the geometrical dimensions of the structure. The dependencies of the linear, nonlinear and total optical absorption coefficients as functions of the incident photon energy are investigated for different values of those mentioned parameters. It is found that the influences mentioned above lead to either redshifts or blueshifts of the resonant peaks of the optical absorption spectrum. It is particularly discussed the unusual property exhibited by the third-order nonlinear of becoming positive for photon energies below the resonant transition one. It is shown that this phenomenon is associated with the particular features of the system under study, which determine the values of the electric dipole moment matrix elements.
-
binding energy of hydrogenic donor impurity in gaas ga1 xalxas concentric double quantum rings effects of geometry hydrostatic pressure temperature and Aluminum Concentration
Physica E-low-dimensional Systems & Nanostructures, 2013Co-Authors: H.m. Baghramyan, C.a. Duque, M G Barseghyan, A A KirakosyanAbstract:Abstract We consider the effects of hydrostatic pressure, temperature, Aluminum Concentration and impurity position on hydrogen-like donor binding energy in GaAs / Ga 1 − x Al x As concentric double quantum rings. The ground state energy and the impurity wave function are calculated using the variational method. For the hydrostatic pressure effects the Γ − X crossover has been taken into account. The probability density of electron without electron-impurity interaction have been investigated for different values of the sizes of the structure. The dependencies of the binding energy on geometry of the structure, hydrostatic pressure, temperature, Aluminum Concentration and impurity positions have been also investigated. The results show that the binding energy is an increasing (decreasing) function of the hydrostatic pressure and Aluminum Concentration (temperature). Additionally we have found that when the impurity is placed within the inner ring, the binding energy behavior strongly depends on the widths of the outer ring and coupling barrier.
Tatsuhiko Aizawa - One of the best experts on this subject based on the ideXlab platform.
-
effect of Aluminum Concentration on friction and wear properties of titanium Aluminum nitride films
Surface & Coatings Technology, 2004Co-Authors: H Ohnuma, Nobuhiro Nihira, Atsushi Mitsuo, K Toyoda, K Kubota, Tatsuhiko AizawaAbstract:Abstract It is well known that the hard thin ceramic films are utilized to industrial applications such as cutting tools, molding dies and sliding parts, because of its effect of reducing the wear. Recently, the demand of TiAlN film is expanding, because it has a high oxidation resistance at elevated temperature as well as good wear resistance. In this paper, friction and wear properties of TiAlN films having various Concentration ratios of Ti/Al have been studied. The films were deposited by a cathodic arc ion plating method on cemented carbide substrate with a thickness of approximately 3 μm. Composition of the deposited film was evaluated by energy dispersive X-ray spectroscopy. Crystal structure of the deposited film was characterized by X-ray diffraction. Hardness of the films was measured by a nano-indentation tester. Friction and wear tests were carried out by a pin-on-disk tribometer at 300, 473, 673 and 873 K. Compositions of the films deposited from cathode materials that have atomic ratios (Ti:Al) of 50:50, 34:66 and 25:75 in TiAl alloys were Ti 0.6 Al 0.4 N, Ti 0.42 Al 0.58 N and Ti 0.3 Al 0.7 N, respectively. The crystal structure of Ti 0.6 Al 0.4 N Ti 0.42 Al 0.58 N and Ti 0.3 Al 0.7 N were found to be a B1, B4+B1 and B4, respectively. Nano-hardness decreased with increasing Al content in the films. There is no correlation between friction coefficient of each film and test temperature. The width of wear track for each film decreased above the temperature of 673 K. Ti 0.6 Al 0.4 N film was worn less than the other films at 873 K.
