New state of a 2D electron crystal above liquid helium

A transition to a new, presumably unstable, state of a two-dimensional (2D) electron crystal above liquid helium has been discovered at temperatures well below the melting point. The transition is manifested as an abrupt increase in the active component of the inverse conductivity of the crystal with a decrease in the potential pressing of the electrons to the surface. The state can be destroyed by the in-plane electric field of a sufficiently high amplitude. The new state is supposed to be a 2D electron glass.