1. Quadrature coherence scale driven fast decoherence of bosonic quantum field states
- Author
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Anaelle Hertz, Stephan De Bièvre, Laboratoire Paul Painlevé - UMR 8524 (LPP), Université de Lille-Centre National de la Recherche Scientifique (CNRS), Paradyse, Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Inria Lille - Nord Europe, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), This work was supported in part by the Labex CEMPI (ANR-11-LABX-0007-01) and by the Nord-Pas de Calais Regional Council and FEDER through the Contrat de Projets Etat-R´egion (CPER). SDB thanks Prof. H. Spohn and J.C. Garreau for illuminating discussions on the subject matter of the paper. SDB thanks the CRM, where this work was initiated, for its hospitality in October-November 2018., ANR-11-LABX-0007,CEMPI,Centre Européen pour les Mathématiques, la Physique et leurs Interactions(2011), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 (PhLAM), Centre National de la Recherche Scientifique (CNRS)-Université de Lille, Laboratoire Paul Painlevé (LPP), Systèmes de particules et systèmes dynamiques (Paradyse), Laboratoire de Physique des Lasers, Atomes et Molécules - UMR 8523 [PhLAM], and Laboratoire Paul Painlevé [LPP]
- Subjects
Coupling ,Physics ,Quantum Physics ,[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics] ,Quantum decoherence ,etc ,General Physics: Statistical and Quantum Mechanics ,General Physics and Astronomy ,FOS: Physical sciences ,01 natural sciences ,Measure (mathematics) ,[PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph] ,Quadrature (mathematics) ,Quantum Information ,Quantum mechanics ,0103 physical sciences ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Wigner distribution function ,Quantum field theory ,Quantum information ,010306 general physics ,Quantum Physics (quant-ph) ,Coherence (physics) - Abstract
We introduce, for each state of a bosonic quantum field, its quadrature coherence scale (QCS), a measure of the range of its quadrature coherences. Under coupling to a thermal bath, the purity and QCS are shown to decrease on a time scale inversely proportional to the QCS squared. The states most fragile to decoherence are therefore those with quadrature coherences far from the diagonal. We further show a large QCS is difficult to measure since it induces small scale variations in the state's Wigner function. These two observations imply a large QCS constitutes a mark of "macroscopic coherence". Finally, we link the QCS to optical classicality: optical classical states have a small QCS and a large QCS implies strong optical nonclassicality., 12 pages, 5 figures. New version to match the published version. Minor errors were corrected
- Published
- 2020
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