In situ tuning of symmetry-breaking induced non-reciprocity in giant-Rashba semiconductor BiTeBr

TL;DR

This paper demonstrates in-situ tuning of non-reciprocal transport in BiTeBr, a giant-Rashba semiconductor, via ionic-liquid gating, achieving over 400% variation in response, highlighting a novel method for controlling exotic nanocrystals.

Contribution

It introduces a new ionic-liquid gating technique with a protective hBN layer to tune non-reciprocal effects in BiTeBr in situ.

Findings

Over 400% variation in non-reciprocal response achieved

Ionic-liquid gating effective through hBN protective layer

Method enables control of carrier density in sensitive nanocrystals

Abstract

Non-reciprocal transport, where the left to right flowing current differs from the right to left flowing one, is an unexpected phenomenon in bulk crystals. BiTeBr is a non-centrosymmetric material, with a giant Rashba spin-orbit coupling which presents this unusual effect when placed in an in-plane magnetic field. It has been shown that this effect depends strongly on the carrier density, however, in-situ tuning has not yet been demonstrated. We developed a method where thin BiTeBr flakes are gate tuned via ionic-liquid gating through a thin protective hBN layer. Tuning the carrier density allows a more than \SI{400}{\percent} variation of the non-reciprocal response. Our study serves as a milestone on how a few-atomic-layer-thin van der Waals protection layer allows ionic gating of chemically sensitive, exotic nanocrystals.