Coherent Control of Transmission Probability of a Cold Atom Through Microcavity Potentials

We investigate the transmission probability of a two-level cold atom through a quantum microcavity when the atom is initially prepared in a coherent superposition of its excited state and ground state. We can control the transmissibility of the atom by this initial coherence. Remarkable step and switch effect are discovered in the atomic transmission for the case of weak and intense quantized fields, respectively.