Spin current diode based on an electron waveguide with spin-orbit interaction

TL;DR

This paper introduces a spin current diode utilizing a hornlike electron waveguide with Rashba spin-orbit interaction, demonstrating directional control of spin conductance even at small biases, based on spin-flipped transitions.

Contribution

It presents a novel device design for a spin current diode that operates effectively in the linear-response regime, leveraging spin-orbit interaction-induced spin-flipped transitions.

Findings

Spin conductance remains constant when electrons come from the narrow lead.

Reversing the transport direction suppresses spin conductance significantly.

Device operates effectively at small applied biases.

Abstract

We propose a spin current diode which can work even in a small applied bias condition (the linear-response regime). The prototypal device consists of a hornlike electron waveguide with Rashba spin-orbit interaction, which is connected to two leads with different widths. It is demonstrated that when electrons are incident from the narrow lead, the generated spin conductance fluctuates around a constant value in a wide range of incident energy. When the transport direction is reversed, the spin conductance is suppressed strongly. Such a remarkable difference arises from spin-flipped transitions caused by the spin-orbit interaction.