Phase diffusion pattern in quantum nondemolition systems
Abstract
We quantitatively analyze the dynamics of the quantum phase distribution associated with the reduced density matrix of a system, as the system evolves under the influence of its environment with an energy-preserving quantum nondemolition (QND) type of coupling. We take the system to be either an oscillator (harmonic or anharmonic) or a two-level atom (or equivalently, a spin-1/2 system), and model the environment as a bath of harmonic oscillators, initially in a general squeezed thermal state. The impact of the different environmental parameters is explicitly brought out as the system starts out in various initial states. The results are applicable to a variety of physical systems now studied experimentally with QND measurements.
Cite
@article{arxiv.quant-ph/0703055,
title = {Phase diffusion pattern in quantum nondemolition systems},
author = {Subhashish Banerjee and Joyee Ghosh and R. Ghosh},
journal= {arXiv preprint arXiv:quant-ph/0703055},
year = {2009}
}
Comments
18 pages, REVTeX, 8 figures