We have calculated quasi-bound-state energies and lifetimes of surface-state electrons above liquid helium for two single-particle potentials. In the first case, the electric field due to other electrons is taken to be that of a uniform charge sheet. The second is an effective one-particle potential that includes correlation effects in a simple manner. We solved the Schrödinger equation numerically to determine the asymptotic amplitude and the phase of the wave function, from which resonances and their widths are obtained. Tunneling rates and thermal activation energies are calculated as a function of correlation-hole radius, electron density, and pressing electric field amplitude. We compare these results with recent experiments.

• Received 27 February 1990

DOI:https://doi.org/10.1103/PhysRevB.42.2088