Dynamic Properties of the Two-Dimensional Wigner Solid on the Surface of Normal and Superfluid 3He

Abstract

We present the theory of transport properties and vibration modes of the two-dimensional Wigner solid (WS) coupled to surface dimples on normal and superfluid 3 He. Compared to the case of liquid 4 He, Fermi liquid properties of the substrate crucially affect the low-frequency dynamics of the electron solid. At ultralow temperatures, WS transport is shown to be determined mostly by the reflection of ballistic quasiparticles of the bulk liquid at the dimple sublattice. The long mean free path regime of normal 3 He is characterized by the temperature-independent conductivity. Below the superfluid transition, the appearance of the quasiparticle energy gap sharply reduces the momentum adsorbed by moving dimples, which leads to the rapid increase of the WS conductivity. The analysis presented shows that the WS can serve as a new powerful experimental probe for superfluid phases of 3 He.