Spin current and polarization reversal through a single-molecule magnet with ferromagnetic electrodes

TL;DR

This paper theoretically investigates spin-polarized transport through a single-molecule magnet with ferromagnetic electrodes, revealing how bias voltage can manipulate spin-current polarization, especially under antiferromagnetic exchange-coupling.

Contribution

It introduces a theoretical framework for understanding spin transport in single-molecule magnets with ferromagnetic leads, highlighting polarization reversal mechanisms.

Findings

Spin current shows step- and basin-like behaviors in different configurations.

Polarization reversal can be achieved by bias voltage in antiferromagnetic coupling.

Bias voltage affects only magnitude in ferromagnetic coupling.

Abstract

We theoretically study the spin-polarized transport through a single-molecule magnet, which is weakly coupled to ferromagnetic leads, by means of the rate-equation approach. We consider both the ferromagnetic and antiferromagnetic exchange-couplings between the molecular magnet and transported electron-spin in the nonlinear tunneling regime. For the ferromagnetic exchangecoupling, spin current exhibits step- and basin-like behaviors in the parallel and antiparallel configurations respectively. An interesting observation is that the polarization reversal of spin-current can be realized and manipulated by the variation of bias voltage in the case of antiferromagnetic exchange-coupling with antiparallel lead-configuration, which may be useful in the development of spintronic devices, while the bias voltage can only affect the magnitude of spin-polarization in the ferromagnetic coupling.