2007/03/31 by Subhashish Banerjee, Joyee Ghosh, R. Ghosh
Computer Science · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Anharmonicity #Coupling (piping) #Density matrix #Harmonic #Harmonic oscillator #Materials science #Phase (matter) #Physics #Quantum #Quantum Information and Cryptography #Quantum mechanics #Quantum system #Spectroscopy and Quantum Chemical Studies #Statistical physics #cond-mat.stat-mech #quant-ph
paper · pdf · doi:10.1103/physreva.75.062106
published as Phys. Rev. A 75, 062106 (2007) · 18 pages, REVTeX, 8 figures
openalex publication_date 2007/06/14 · arxiv created 2007/06/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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.