Study of couplings effect on the performance of a spin-current diode: Nonequilibrium Green's function based model

TL;DR

This paper investigates how coupling strength and magnetic field influence spin-dependent transport in a quantum dot spin diode, using a nonequilibrium Green's function approach that simplifies calculations without self-consistency.

Contribution

It introduces a new method for computing Green's functions in spin diodes without self-consistent calculations and analyzes the effects of coupling and magnetic field on device performance.

Findings

Device cannot function as a spin diode under certain conditions

Coupling strength significantly affects spin current

Magnetic field influences spin accumulation

Abstract

In this paper, spin-dependent transport through a spin diode composed of a quantum dot coupled to a normal metal and a ferromagnetic lead is studied. The current polarization and the spin accumulation are analyzed using the equations of motion method within the nonequilibrium Green's function formalism. We present a suitable method for computing Green's function without carrying out any self-consistent calculation. The influence of coupling strength and magnetic field on the spin current is studied and observed that this device cannot work as a spin diode under certain conditions.