2019/09/30 by Anaelle Hertz, Stephan De Bièvre · 20 citations
Computer Science · Mathematics · Physics and Astronomy · #Coherence (philosophical gambling strategy) #Field (mathematics) #Mathematics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum decoherence #Quantum electrodynamics #Quantum mechanics #Scale (ratio) #Statistical physics #quant-ph
paper · pdf · doi:10.1103/physrevlett.124.090402
published in Physical Review Letters 124(9), 090402 (American Physical Society) · 12 pages, 5 figures. New version to match the published version. Minor errors were corrected
openalex publication_date 2020/03/05 · arxiv created 2020/03/11 · arxiv updated 2020/03/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
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 timescale 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.