The phenomenon of decoherence appears when the quantum behaviour of a microsystem is investigated. If the shielding of the considered microsystem from the macroscopic environment is not perfect, typical quantum features, such as the capability to exhibit quantum fringes, are suppressed as an unavoidable result of the interaction with the macroscopic background. Focusing on the centre of mass degrees of freedom of a massive test particle decoherence can typically be described in terms of random momentum transfers with the environment, thus naturally calling for a probabilistic standpoint. In this framework a general connection between the characteristic function of a Lévy process and loss of coherence of a massive quantum system interacting through momentum transfer events with an environment will be put into evidence, relying on Holevo's characterization of quantum dynamical semigroups in the presence of translational invariance. The relationship with microphysical models and recent experiments on decoherence will also be considered.
A probabilistic view on decoherence theory / B. Vacchini (AIP CONFERENCE PROCEEDINGS). - In: Foundations of probability and physics 4 / [a cura di] G. Adenier, C. A. Fuchs, A. Yu. Khrennikov. - Melville : American institute of physics, 2007. - ISBN 9780735403918. - pp. 427-431 (( Intervento presentato al 4. convegno Foundations of probability and physics tenutosi a Vaxjo, Sweden nel 2006 [10.1063/1.2713491].
A probabilistic view on decoherence theory
B. VacchiniPrimo
2007
Abstract
The phenomenon of decoherence appears when the quantum behaviour of a microsystem is investigated. If the shielding of the considered microsystem from the macroscopic environment is not perfect, typical quantum features, such as the capability to exhibit quantum fringes, are suppressed as an unavoidable result of the interaction with the macroscopic background. Focusing on the centre of mass degrees of freedom of a massive test particle decoherence can typically be described in terms of random momentum transfers with the environment, thus naturally calling for a probabilistic standpoint. In this framework a general connection between the characteristic function of a Lévy process and loss of coherence of a massive quantum system interacting through momentum transfer events with an environment will be put into evidence, relying on Holevo's characterization of quantum dynamical semigroups in the presence of translational invariance. The relationship with microphysical models and recent experiments on decoherence will also be considered.Pubblicazioni consigliate
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