Evidence for a Bilayer Quantum Wigner Solid

TL;DR

This paper presents experimental evidence for a bilayer Wigner solid phase in a quantum well system, showing how interlayer interactions stabilize a correlated insulating state at high filling factors.

Contribution

It provides the first experimental indication of a pinned bilayer Wigner solid forming at relatively high filling factors due to interlayer interactions.

Findings

Observation of an insulating phase evolving with charge distribution

Evidence of a correlated bilayer electron insulator

Wigner solid crystallization at total filling factor as high as 0.54

Abstract

As the electronic charge distribution in a wide quantum well is tuned from a single-layer through an interacting bilayer configuration to weakly-coupled parallel layers, we observe an insulating phase concurrently manifesting a dramatic evolution. The data reveal that interlayer interactions, playing a crucial role, are able to stabilize a {\it correlated bilayer} electron insulator, thus providing tantalizing evidence of a pinned bilayer Wigner solid phase crystallizing at total filling factor $\nu$ as large as 0.54 ($\nu > \frac14$ in each layer).