title: Exact decoherence to pointer states in free open quantum systems is universal.
abstract: In this Letter it is shown that exact decoherence to minimal uncertainty Gaussian pointer states is generic for free quantum particles coupled to a heat bath. More specifically, the Letter is concerned with damped free particles linearly coupled under product initial conditions to a heat bath at arbitrary temperature, with arbitrary coupling strength and spectral densities covering the Ohmic, sub-Ohmic, and supra-Ohmic regime. Then it is true that there exists a time t(c) such that for times t>t(c) the state can always be exactly represented as a mixture (convex combination) of particular minimal uncertainty Gaussian states, regardless of and independent from the initial state. This exact "localization" is hence not a feature specific to high temperature and weak damping limit, but is a generic property of damped free particles.
authors.affiliation: Institut für Physik, Universität Potsdam, Am Neuen Palais 10, D-14469 Potsdam, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Eisert