Abstract

Decoherence, i.e., the rapid destruction of the phase relation between two quantum states of a system caused by the entanglement of these two states with two different states of the environment,¹ is the main limiting factor for quantum information processing. For this reason decoherence control is now becoming a rapidly expanding field of investigation. The progressive decoherence of a mesoscopic Schrodinger cat state has been observed for the first time in the experiment of Brune et al.,² where the linear superposition of two coherent states of a field in a microwave cavity, with classically distinct phases, has been generated and detected.

© 1999 Optical Society of America