Fractional quantum Hall effect in CdTe

TL;DR

This paper reports the observation of fractional quantum Hall states in a high mobility CdTe quantum well at very low temperatures, highlighting spin polarization and Landau level phenomena.

Contribution

First observation of FQH states in CdTe quantum wells, demonstrating spin polarization and Landau level effects in this material system.

Findings

FQH states at filling factors 4/3 and 5/3 are fully developed.

FQH minima observed at 7/3 and 8/3 in the first excited Landau level.

FQH states are spin-polarized with high intrinsic Zeeman energy.

Abstract

The fractional quantum Hall (FQH) effect is reported in a high mobility CdTe quantum well at mK temperatures. Fully-developed FQH states are observed at filling factor 4/3 and 5/3 and are found to be both spin-polarized ground state for which the lowest energy excitation is not a spin-flip. This can be accounted for by the relatively high intrinsic Zeeman energy in this single valley 2D electron gas. FQH minima are also observed in the first excited (N=1) Landau level at filling factor 7/3 and 8/3 for intermediate temperatures.