Quantum reflection of metastable hydrogen atoms by a conducting surface

Abstract

Due to the degeneracy of the n = 2 states, the potential between a metastable 2 S hydrogen atom and a conducting surface falls off as − 1 / z 3 asymptotically, in contrast to the usual retarded van der Waals potentials, which fall off as − 1 / z 4 . This affects the quantum reflection amplitudes and causes the apparent space shifts, which express the time involved in the quantum reflection process, to diverge to large negative values at threshold.