Efficient spin current source using a half-Heusler alloy topological semimetal with Back-End-of-Line compatibility

TL;DR

This paper introduces a half-Heusler alloy topological semimetal, YPtBi, as an efficient, industry-compatible spin current source with a giant spin Hall effect suitable for ultralow power spintronic devices.

Contribution

It demonstrates that YPtBi achieves a high spin Hall angle and thermal stability, enabling magnetization switching at lower current densities and compatibility with silicon BEOL processes.

Findings

Achieves a spin Hall angle up to 1.6 in YPtBi

Supports thermal budgets up to 600°C

Enables magnetization switching at lower current densities

Abstract

Topological materials, such as topological insulators (TIs), have great potential for ultralow power spintronic devices, thanks to their giant spin Hall effect. However, the giant spin Hall angle (${\theta}_{SH}$ > 1) is limited to a few chalcogenide TIs with toxic elements and low melting points, making them challenging for device integration during the silicon Back-End-of-Line (BEOL) process. Here, we show that by using a half-Heusler alloy topological semi-metal (HHA-TSM), YPtBi, it is possible to achieve both a giant ${\theta}_{SH}$ up to 1.6 and a high thermal budget up to 600${\deg}$C. We demonstrate magnetization switching of a CoPt thin film using the giant spin Hall effect of YPtBi by current densities lower than those of heavy metals by one order of magnitude. Since HHA-TSM includes a group of three-element topological materials with great flexibility, our work opens the door to the third-generation spin Hall materials with both high ${\theta}_{SH}$ and high compatibility with the BEOL process that would be easily adopted by the industry.