Decoherence in phase space
Much of the discussion of decoherence has been in terms of a particle moving in one dimension that is placed in an initial superposition state (a Schrödinger "cat" state) corresponding to two widely separated wave packets. Decoherence refers to the destruction of the interference term in the quantum probability function. Here, we stress that a quantitative measure of decoherence depends not only on the specific system being studied but also on whether one is considering coordinate, momentum, or phase space. We show that this is best illustrated by considering Wigner phase space where the measure is again different. Analytic results for the time development of the Wigner distribution function for a two-Gaussian Schrödinger cat state have been obtained in the high-temperature limit (where decoherence can occur even for negligible dissipation), which facilitates a simple demonstration of our remarks.
Publication Source (Journal or Book title)
Murakami, M., Ford, G., & O'Connell, R. (2003). Decoherence in phase space. Laser Physics, 13 (2), 180-183. Retrieved from https://digitalcommons.lsu.edu/physics_astronomy_pubs/3903