Observation of fractional quantum Hall effect in an InAs quantum well

TL;DR

This paper reports the first observation of the fractional quantum Hall effect in a high-quality InAs quantum well, demonstrating strong electron-electron interactions in a low-disorder system at very low temperatures.

Contribution

It provides experimental evidence of fractional quantum Hall states in InAs quantum wells, a material promising for topological quantum computing applications.

Findings

Observation of a deep minimum in longitudinal resistance at ν=4/3

Nearly quantized Hall plateau at ν=4/3

High mobility and low disorder in the InAs quantum well

Abstract

The two-dimensional electron system in an InAs quantum well has emerged as a prime candidate for hosting exotic quasi-particles with non-Abelian statistics such as Majorana fermions and parafermions. To attain its full promise, however, the electron system has to be clean enough to exhibit electron-electron interaction phenomena. Here we report the observation of fractional quantum Hall effect in a very low disorder InAs quantum well with a well-width of 24 nm, containing a two-dimensional electron system with a density $n=7.8 \times 10^{11}$ cm$^{-2}$ and low-temperature mobility $1.8 \times 10^6$ cm$^2$/Vs. At a temperature of $\simeq35$ mK and $B\simeq24$ T, we observe a deep minimum in the longitudinal resistance, accompanied by a nearly quantized Hall plateau at Landau level filling factor $\nu=4/3$.