Ripplonic Polarons in a Wigner Crystal

Abstract

By the use of the path-integral method, general formula of the free energy and the conductivity of electrons in a two-dimensional Wigner crystal are obtained when both of the electron-electron and the electron-surface interactions are present. The dc conductivity is calculated explicitly for electrons bound on the surface of liquid He in the case of the weak electron-ripplon coupling. Good agreement is obtained between theory and experiment about the density dependence of the collision time.