Thermal spin injection from a ferromagnet into graphene by transverse and longitudinal current

TL;DR

This paper investigates thermal and electrical spin injection in graphene, demonstrating enhanced spin voltage via thermal effects, highlighting graphene's potential for thermoelectric spin devices due to its long spin lifetime and diffusion length.

Contribution

It introduces a novel approach combining thermal and electrical spin injection in graphene, revealing the interplay and enhancement of spin signals near the Dirac point.

Findings

Thermal spin injection enhances non-local spin voltage.

Maximum thermal spin voltage occurs near the Dirac point.

Graphene's long spin lifetime makes it suitable for thermoelectric spin devices.

Abstract

Graphene is a very promising material in spintronics due to both its high electric mobility and low intrinsic spin-obit coupling. Electronic spins can be injected from a ferromagnetic material through a tunnel contact into graphene owing to a spin relaxation length as high as 5{\mu}m. In recent years, a new approach creating spin current employed thermal effects and heat flow. Here, by applying transverse and longitudinal current to a grahene spin valve device, the interplay between the heat spin current and the charge spin current is investigated. The non-local spin voltage is enhanced by the thermal spin injection and the thermal spin voltage reaches a maximum close to the Dirac point which makes graphene a promising material for a future thermoelectric spin device due to its long spin lifetime and spin diffusion length.