Magneto-optical evidence for depinning of the Wigner crystal by an electric field

Abstract
We investigate the influence of an electric field on the radiative recombination of two-dimensional electrons in the Wigner-solid regime. We find a threshold enhancement of the intensity of the luminescence accompanied by the appearance of noise, which we associate with a sliding of the pinned Wigner solid by the electric field. Our results indicate that the melting of the Wigner solid occurs in two steps and can be characterized by two critical temperatures.