ﻻ يوجد ملخص باللغة العربية
The system of equations of self-induced transparency (SIT) for extraordinary wave in uniaxial anisotropic media by means of generalized reduction perturbation method are transformed to the coupled nonlinear Schrodinger equations. It is shown that in the theory of SIT the second derivatives have significant role and leads to the formation of a vector $0pi$ pulse oscillating with the sum and difference of the frequencies. An explicit analytical expressions for the profile and parameters of the nonlinear wave are obtained. It is shown that along with scalar $2pi$ pulse, the vector $0pi$ pulse is also the basic pulse of SIT and the scalar $0pi$ pulse of SIT is only an approximation which can be considered in some special cases. The conditions of the existence of the nonlinear extraordinary wave depends on the direction of propagation. The profile of the vector $0pi$ pulse in anisotropic crystal of ruby is presented with characteristic parameters which usually met in experiments.
We generalize the diffusive model for spin injection and detection in nonlocal spin structures to account for spin precession under an applied magnetic field in an anisotropic medium, for which the spin lifetime is not unique and depends on the spin
We study the influence of particle shape anisotropy on the occurrence of avalanches in sheared granular media. We use molecular dynamic simulations to calculate the relative movement of two tectonic plates. % with transform boundaries. Our model cons
We present ab initio calculations of the evolution of anisotropic magnetoresistance (AMR) in Ni nanocontacts from the ballistic to the tunnel regime. We find an extraordinary enhancement of AMR, compared to bulk, in two scenarios. In systems without
We numerically find that transmission coefficients have a rich structure as a function of wavelength in Cantor media. Complete transmission and complete reflection are observed. We also find that light propagation has scalings with respect to number of layers.
Spin relaxation in graphene is investigated in electrical graphene spin valve devices in the non-local geometry. Ferromagnetic electrodes with in-plane magnetizations inject spins parallel to the graphene layer. They are subject to Hanle spin precess