References & Citations
Quantum Physics
Title: Transverse quantum decoherence of a fast particle in a gas
(Submitted on 27 Nov 2022 (v1), last revised 19 Feb 2023 (this version, v2))
Abstract: The decoherence of a fast quantum particle in a gas is studied by applying the Kramers-Moyal expansion to the quantum master equation for the reduced density matrix of the particle. This expansion leads to a general form of the Caldeira-Leggett master equation accounting for the angular variation of the differential cross section. The equation describes the decoherence in both the longitudinal and transverse directions with respect to the particle motion. It is shown that, when the differential cross section is concentrated in the forward direction, transverse decoherence dominates. The coherence region off the diagonal of the density matrix is characterized by coherence lengths, which can be deduced, for Gaussian states, from the momentum covariance matrix according to a Heisenberg-type uncertainty relation. Finally, the longitudinal-to-transverse ratio of the coherence lengths is estimated for an alpha particle of a few MeVs. This ratio indicates that the coherence region looks like an ellipsoid elongated in the direction of motion.
Submission history
From: David Gaspard [view email][v1] Sun, 27 Nov 2022 13:04:21 GMT (215kb,D)
[v2] Sun, 19 Feb 2023 12:20:19 GMT (216kb,D)
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