The physics of an ensemble of oscillating two-state particles and antiparticles, interacting elastically and inelastically with a heat bath and particle reservoir, is examined. In particular, the effect that the interactions have on the quantum coherence, or superposition, between the two intrinsic degrees of freedom, is discussed. To examine the behavior of the system, ideas from quantum measurement and information theory are employed.

• Received 4 June 1991

DOI:https://doi.org/10.1103/PhysRevA.45.2243