Efficient spin-to-charge interconversion in Weyl semimetal TaP at room temperature

TL;DR

This study demonstrates efficient room-temperature spin-to-charge conversion in Weyl semimetal TaP via the inverse Rashba-Edelstein effect, showing a significantly larger conversion coefficient than graphene and comparable to topological insulators.

Contribution

First experimental demonstration of room-temperature spin-to-charge conversion in Weyl semimetal TaP using IREE with a high conversion efficiency.

Findings

Measured IREE coefficient of 0.30 nm in TaP.

Observed symmetric voltage signals indicating pure spin-to-charge conversion.

Compared efficiency favorably to graphene and topological insulators.

Abstract

In this paper we present spin-to-charge current conversion properties in the Weyl semimetal TaP by means of the inverse Rashba-Edelstein effect (IREE) with the integration of this quantum material with the ferromagnetic metal Permalloy $(Py=Ni_{81}Fe_{19})$. The spin currents are generated in the Py layer by the spin pumping effect (SPE) from microwave-driven ferromagnetic resonance and are detected by a dc voltage along the TaP crystal, at room temperature. We observe a field-symmetric voltage signal without the contamination of asymmetrical lines due to spin rectification effects observed in studies using metallic ferromagnets. The observed voltage is attributed to spin-to-charge current conversion based on the IREE, made possible by the spin-orbit coupling induced intrinsically by the bulk band structure of Weyl semimetals. The measured IREE coefficient ${\lambda}_{IREE}=(0.30 \pm{0.01})$ nm is two orders of magnitude larger than in graphene and is comparable to or larger than the values reported for some metallic interfaces and for several topological insulators.