Two-dimensional electrons at a cleaved semiconductor surface: Observation of the quantum Hall effect

TL;DR

This study reports the observation of the quantum Hall effect in a two-dimensional electron system formed on cleaved InAs surfaces, demonstrating perfect 2D behavior and Rashba spin splitting at low temperatures.

Contribution

First direct observation of quantum Hall effect and Rashba spin splitting in surface electrons on cleaved InAs, confirming 2D electron behavior and surface donor model.

Findings

Quantized Hall resistance observed

Zero longitudinal resistivity confirmed 2D system

Rashba effect detected due to asymmetric potential

Abstract

Low-temperature in-plane magnetotransport measurements have been performed on adsorbate-induced electron systems formed at in-situ cleaved surfaces of p-type InAs. The Ag-coverage dependence of the surface electron density strongly supports a simple model based on a surface donor level lying above the conduction band minimum. The observations of the quantized Hall resistance and zero longitudinal resistivity demonstrate the perfect two-dimensionality of the surface electron system. We also observed the Rashba effect due to the strong asymmetry of the confining potential well.