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Different energy shifts for majority and minority electrons occur. Thus, for example in case of (laser) excited ferromagnetic metals majority and minority electrons may respond differently in time during closing the exchange splitting. Spin flip transitions of the hot electrons due to electron interactions cause quasi hybridization of the spin split states. This is also the case in itinerant ferromagnetic metals due to hopping between sites having magnetic moments pointing in direction of the magnetization (+) and opposite direction (-) and with energy levels $varepsilon^+_{isigma}$ and $varepsilon^-_{isigma}$. For energetic reasons the molecular field acts asymmetrically on the spins of the electrons and on spin flip transitions and thus causes different lifetimes of minority and majority electrons and spin dependent electron energy shifts. Quite general minority hot electrons in spin split states may respond faster than majority electrons at non--equilibrium. The molecular field acting on the spins delays spin flip transitions $uparrow rightarrow downarrow$ and thus a response of the hot majority electrons and their energy levels. The closing of the exchange splitting in the electron spectrum of ferromagnetic transition and rare--earth metals, ferromagnetic semiconductors, spin split quantum well states in thin ferromagnetic films, etc. will reflect this. The time and spin dependent energy shifts of electrons at non--equilibrium may cause interesting behavior, in particular of magnetic tunnel junctions, spin currents etc.. In ferromagnets the moment reversal lifetime of (local) magnetic moments parallel to the global magnetization is larger than of moments pointing in opposite direction.
We investigate the spin dynamics of high-mobility two-dimensional electrons in GaAs/AlGaAs quantum wells grown along the $[001]$ and $[110]$ directions by time-resolved Faraday rotation at low temperatures. In measurements on the $(001)$-grown struct
The conducting polymer polyaniline (PANI) has a wide range of optoelectronic applications due to its unique electronic and optical characteristics. Although extensive works have been performed to understand the equilibrium properties, the nature of t
We demonstrate a novel method for the excitation of sizable magneto-optical effects in Au by means of the laser-induced injection of hot spin-polarized electrons in Au/Fe/MgO(001) heterostructures. It is based on the energy- and spin-dependent electr
We analyze the energy spectrum of graphene in the presence of spin-orbit coupling and a unidirectionally periodic Zeeman field, focusing on the stability and location of Dirac points it may support. It is found that the Dirac points at the $K$ and $K
Spin-Hall conductivity (SHC) of fully relativistic (4x4 matrix) Dirac electrons is studied based on the Kubo formula aiming at possible application to bismuth and bismuth-antimony alloys. It is found that there are two distinct contributions to SHC,