Nonequilibrium itinerant-electron magnetism: A time-dependent mean-field theory

作者:Secchi A*; Lichtenstein A I; Katsnelson M I
来源:Physical Review B, 2016, 94(8): 085153.
DOI:10.1103/PhysRevB.94.085153

摘要

We study the dynamical magnetic susceptibility of a strongly correlated electronic system in the presence of a time-dependent hopping field, deriving a generalized Bethe-Salpeter equation that is valid also out of equilibrium. Focusing on the single-orbital Hubbard model within the time-dependent Hartree-Fock approximation, we solve the equation in the nonequilibrium adiabatic regime, obtaining a closed expression for the transverse magnetic susceptibility. From this, we provide a rigorous definition of nonequilibrium (time-dependent) magnon frequencies and exchange parameters, expressed in terms of nonequilibrium single-electron Green's functions and self-energies. In the particular case of equilibrium, we recover previously known results.

  • 出版日期2016-8-31