TUNNELING THROUGH MOVING BARRIERS

In this paper we present a variety of theoretical methods to treat the general problem of a quantum particle interacting with a time-dependent barrier. Assuming a sinusoidal form for the time dependence, we discuss the classical, semiclassical and quantum solutions for two specific problems: a barrier whose amplitude is modulated, and one whose mean position changes. While the classical solutions to these problems are quite different, the time-dependent quantum solutions appear almost identical. It is only when the particle is modelled as a wavepacket that the quantum solutions behave like their classical counterparts.