Electrically tunable spin-orbit interaction in an InAs nanosheet

TL;DR

This study demonstrates how the spin-orbit interaction in an InAs nanosheet can be electrically tuned using a dual-gate device, revealing control over electron transport regimes and insights into Rashba and Dresselhaus SOI types.

Contribution

It provides experimental evidence of electrical tuning of spin-orbit interaction in a free-standing InAs nanosheet with dual gates, including detailed transport analysis and band diagram simulations.

Findings

Spin-orbit interaction can be tuned from weak antilocalization to localization and back.

A peak in spin-orbit length indicates suppression of Rashba SOI.

Simulations support experimental observations of band structure and SOI behavior.

Abstract

We report on an experimental study of the spin-orbit interaction (SOI) in an epitaxially grown free-standing InAs nanosheet in a dual-gate field-effect device. Gate-transfer characteristic measurements show that independent tunings of the carrier density in the nanosheet and the potential difference across the nanosheet can be efficiently achieved with use of the dual gate. The quantum transport characteristics of the InAs nanosheet are investigated by magnetoconductance measurements at low temperatures. It is shown that the electron transport in the nanosheet can be tuned from the weak antilocalization to the weak localization and then back to the weak antilocalization regime with a voltage applied over the dual gate without a change in carrier density. The spin-orbit length extracted from the magnetoconductance measurements at a constant carrier density exhibits a peak value at which the SOI of the Rashba type is suppressed and the spin relaxation due to the presence of an SOI of the Dresselhaus type in the nanosheet can be revealed. Energy band diagram simulations have also been carried out for the device at the experimental conditions and the physical insights into the experimental observations have been discussed in light of the results of simulations.