Exchange and correlation effects on spin Coulomb drag in a spin-polarized quasi-one-dimensional electron gas

Abstract

In this paper, we study the spin Coulomb drag (SCD) effect in a spin-polarized quasi-one-dimensional electron gas (Q1DEG) by including the exchange-correlation effects within the self-consistent mean-field approximation of Singwi, Tosi, Land, and Sjölander (the STLS theory). Numerical results for the spin drag rate [Formula: see text] are presented over a wide range of temperature T, some selected values of electron number density [Formula: see text] and spin-polarization. We note that for unpolarized Q1DEG, [Formula: see text] is maximum and then decreases with increase in spin-polarization at each T and/or [Formula: see text]. As an important finding, we report that for a set of critical system parameters at which a long-wavelength spin-density-wave (SDW) instability has been recently reported to occur in a Q1DEG, the drag intensity function attains maxima and [Formula: see text] increases abruptly. However, the random-phase approximation (RPA) underestimates [Formula: see text] in comparison to the STLS theory over a broad range of T and the difference becomes quite appreciable in strongly correlated regime (sufficiently low T and high [Formula: see text]). In addition, we report for the first time the spin-plasmon dispersion of spin-polarized Q1DEG and find that the increase in degree of spin-polarization causes the spectrum to reduce in energy significantly. Besides, the spin-plasmon modes at finite spin-polarization show a consistent blue shift with rise in T and/or [Formula: see text], and the RPA largely overestimates them.