3/2 fractional quantum Hall plateau in confined two-dimensional electron gas

Hailong Fu,Yijia Wu,Zheyi Zhu,K W West,Ruoxi Zhang,Pengjie Wang,Pujia Shan,X C Xie,Jian Sun,Haiwen Liu,L N Pfeiffer,Xi Lin

doi:10.1038/s41467-019-12245-y

Abstract

Even-denominator fractional quantum Hall (FQH) states, such as 5/2 and 7/2, have been well known in a two-dimensional electron gas (2DEG) for decades and are still investigated as candidates of non-Abelian statistics. In this paper, we present the observation of a 3/2 FQH plateau in a single-layer 2DEG with lateral confinement at a bulk filling factor of 5/3. The 3/2 FQH plateau is quantized at left( {frac{h}{{e^2}}} right)/left( {frac{3}{2}} right) within 0.02%, and can survive up to 300 mK. This even-denominator FQH plateau may imply intriguing edge structure and excitation in FQH system with lateral confinement. The observations in this work demonstrate that understanding the effect of the lateral confinement on the many-body system is critical in the pursuit of important theoretical proposals involving edge physics, such as the demonstration of non-Abelian statistics and the realization of braiding for fault-tolerant quantum computation.

Highlights

Even-denominator fractional quantum Hall (FQH) states, such as 5/2 and 7/2, have been well known in a two-dimensional electron gas (2DEG) for decades and are still investigated as candidates of non-Abelian statistics
The observations in this work demonstrate that understanding the effect of the lateral confinement on the many-body system is critical in the pursuit of important theoretical proposals involving edge physics, such as the demonstration of non-Abelian statistics and the realization of braiding for fault-tolerant quantum computation
The 1/3 FQH state can be mapped into the filling factor ν = 1 integer quantum Hall (IQH) state of composite fermions carrying fractional charge of e/3, which leads to a fractional

Summary

Introduction

Even-denominator fractional quantum Hall (FQH) states, such as 5/2 and 7/2, have been well known in a two-dimensional electron gas (2DEG) for decades and are still investigated as candidates of non-Abelian statistics. The discovery of the first even-denominator state, the 5/2 FQH state[6,7], viewed as a paired state of composite fermions with e/4 fractional charge[8], further enriched the knowledge of interacting electrons. Recent studies such as phase transition to the stripe phase[9], and evendenominator states in other two-dimensional systems[10,11], keep providing interesting physics at even-denominator filling factors

Methods

Results

Conclusion