Optical and Hall conductivities of a thermally disordered two-dimensional spin-density wave: Two-particle response in the pseudogap regime of electron-doped high- T c superconductors

摘要: We calculate the frequency-dependent longitudinal ({sigma}{sub xx}) and Hall xy}) conductivities for two-dimensional metals with thermally disordered antiferromagnetism using a generalization of theoretical model, involving one-loop quasistatic fluctuation approximation, which was previously used to electron self-energy. The are calculated from Kubo formula, current vertex function treated in conserving approximation satisfying Ward identity. In order obtain finite dc limit, we introduce phenomenologically impurity scattering, characterized by relaxation time {tau}. {sigma}{sub xx}({Omega}) satisfies f-sum rule. For infinitely peaked spin-correlation function, {chi}(q){proportional_to}{delta}(q-Q), recover expressions mean-field theory ordered state. When length {zeta} is large but finite, both xx} xy} show behaviors characteristic state long-range order. calculation runs into difficulty {Omega} {approx} 1/{tau}.