Spin-Polarized Transport in Ferromagnet-Marginal Fermi Liquid Systems

TL;DR

This paper investigates spin-polarized transport in a system where a marginal Fermi liquid interacts with ferromagnets, revealing deviations from ohmic behavior, temperature effects, and the decay of tunnel magnetoresistance.

Contribution

It introduces a nonequilibrium Green function approach to analyze spin transport in MFL systems, highlighting unique temperature and bias voltage dependencies.

Findings

Current-voltage characteristics deviate from ohmic behavior.

Tunnel magnetoresistance decays exponentially with bias voltage.

TMR decreases slowly with increasing temperature.

Abstract

Spin-polarized transport through a marginal Fermi liquid (MFL) which is connected to two noncollinear ferromagnets via tunnel junctions is discussed in terms of the nonequilibrium Green function approach. It is found that the current-voltage characteristics deviate obviously from the ohmic behavior, and the tunnel current increases slightly with temperature, in contrast to those of the system with a Fermi liquid. The tunnel magnetoresistance (TMR) is observed to decay exponentially with increasing the bias voltage, and to decrease slowly with increasing temperature. With increasing the coupling constant of the MFL, the current is shown to increase linearly, while the TMR is found to decay slowly. The spin-valve effect is observed.