Two-Dimensional Crystallization of the Electrons in MOS Structures Induced by Strong Magnetic Field

Abstract

The phonon dispersion relation of the Wigner lattice in MOS inversion layers under strong magnetic field is investigated by the effective Hamiltonian for the center coordinates of the cyclotron motion. The transverse phonon velocity is calculated in the self-consistent harmonic approximation as a function of the temperature for various carrier concentrations and for various values of the impurity potential strength. The phase diagram is obtained by plotting the critical concentration for the vanishing of the real solution of the phonon velocity. The calculated melting concentration is compared with the observed immobile carrier density in the Si MOS.