Coherent States and the Forced Quantum Oscillator

Abstract

It is shown that the forced quantum oscillator subject to a transient classical force is easily described in terms of the “coherent states”recently found useful in the description of light from optical masers. The natural role these states play in understanding the notions of the phase of a quantum oscillator and the transition to the classical limit is also explained. Very simple derivations of the state vectors, energy transfer, and various transition probabilities are given.