Spin Seebeck Effect in Asymmetric Four-Terminal Systems with Rashba Spin-Orbit Coupling

TL;DR

This paper introduces a novel spin Seebeck effect in asymmetric four-terminal systems with Rashba spin-orbit coupling, enabling spin current generation without magnetic fields and tunable by temperature differences.

Contribution

It demonstrates a new type of spin Seebeck effect arising from Rashba spin-orbit coupling in asymmetric four-terminal systems, including control over spin Seebeck coefficients.

Findings

Spin currents generated along the temperature gradient without magnetic fields.

Simultaneous realization of longitudinal and transverse spin Seebeck effects.

Tunable spin Seebeck coefficients via temperature differences between leads.

Abstract

We propose a new type of the spin Seebeck effect (SSE) emerging from the Rashba spin-orbit coupling in asymmetric four-terminal electron systems. This system generates spin currents or spin voltages along the longitudinal direction parallel to the temperature gradient in the absence of magnetic fields. The remarkable result arises from the breaking of reflection symmetry along the transverse direction. In the meantime, the SSE along the transverse direction, so-called the spin Nernst effect, with spin currents or spin voltages perpendicular to the temperature gradient can be simultaneously realized in our system. We further find that it is possible to use the temperature differences between four leads to tune the spin Seebeck coefficients.