Using quasi time dependent semiclassical transport theory, within relaxation time approximation, we obtained coupled electronic current equations in the presence of time varying field, and based on general scattering ...Using quasi time dependent semiclassical transport theory, within relaxation time approximation, we obtained coupled electronic current equations in the presence of time varying field, and based on general scattering mechanism,. In the vicinity of Dirac points, we find that a characteristic exponent?corresponds to acoustic phonon scattering,?long range Coulomb scattering mechanism and?is short range (delta or contact potential) scattering in which the conductivity is constant of temperature. The?case is the ballistic regime. In the low energy dynamics of Dirac electrons in graphene, the effect of the time dependent electric field is to alter just the electron charge by?making electronic conductivity nonlinear. The effect of constant magnetic field at finite temperature is also considered.展开更多
In present paper, by using of the relaxation times approximation method, we have calculated the oscillation of magnetoresistance (MR) in Fe/Cr superlattice with the thickness of Cr film .A quite good result has been o...In present paper, by using of the relaxation times approximation method, we have calculated the oscillation of magnetoresistance (MR) in Fe/Cr superlattice with the thickness of Cr film .A quite good result has been obtained which is agree with the experiments.展开更多
基金supported by the Joint Funds of the National Natural Science Foundation of China(U1204103)the Science and Technology Research Projects of Education Department of Henan Province(13A110731)~~
文摘Using quasi time dependent semiclassical transport theory, within relaxation time approximation, we obtained coupled electronic current equations in the presence of time varying field, and based on general scattering mechanism,. In the vicinity of Dirac points, we find that a characteristic exponent?corresponds to acoustic phonon scattering,?long range Coulomb scattering mechanism and?is short range (delta or contact potential) scattering in which the conductivity is constant of temperature. The?case is the ballistic regime. In the low energy dynamics of Dirac electrons in graphene, the effect of the time dependent electric field is to alter just the electron charge by?making electronic conductivity nonlinear. The effect of constant magnetic field at finite temperature is also considered.
文摘In present paper, by using of the relaxation times approximation method, we have calculated the oscillation of magnetoresistance (MR) in Fe/Cr superlattice with the thickness of Cr film .A quite good result has been obtained which is agree with the experiments.
