Microwave Resonance of 2D Wigner Crystal around integer Landau fillings

TL;DR

This paper reports microwave absorption measurements revealing a resonance in 2D electron systems near integer Landau fillings, interpreted as evidence of Wigner crystal formation around these levels.

Contribution

It provides the first direct microwave resonance evidence of Wigner crystal states near integer Landau fillings in high-quality 2D electron systems.

Findings

Resonance observed near ν=1 and ν=2

Resonance similar to Wigner crystal in low filling factor regime

Supports Wigner crystal formation around integer Landau levels

Abstract

We have observed a resonance in the real part of the finite frequency diagonal conductivity using microwave absorption measurements in high quality 2D electron systems near {\em integer fillings}. The resonance exists in some neighborhood of filling factor around corresponding integers and is qualitatively similar to previously observed resonance of weakly pinned Wigner crystal in high $B$ and very small filling factor regime. Data measured around both $\nu=1$ and $\nu=2$ are presented. We interpret the resonance as the signature of Wigner crystal state around integer Landau levels.