Evidence for a Bilayer Quantum Wigner Solid

As the electronic charge distribution in a wide quantum well is tuned from a monolayer through an interacting bilayer configuration toward weakly coupled parallel layers, we observe an insulating phase concurrently manifesting a dramatic evolution. The data reveal that both interlayer interactions and charge symmetry, playing crucial roles, are able to stabilize a 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 ($\nu >\frac{1}{4}$ in each layer).