Phase-Space Inequalities Beyond Negativities
Authors: Bohmann M., Agudelo E.
Autors Affiliation: INO CNR, QSTAR, Largo Enrico Fermi 2, I-50125 Florence, Italy; LENS, Largo Enrico Fermi 2, I-50125 Florence, Italy; Austrian Acad Sci, Inst Quantum Opt & Quantum Informat IQOQI Vienna, Boltzmanngasse 3, A-1090 Vienna, Austria
Abstract: We derive a family of inequalities involving different phase-space distributions of a quantum state which have to be fulfilled by any classical state. The violation of these inequalities is a clear signature of nonclassicality. Our approach combines the characterization of nonclassical effects via negativities in phase-space distributions with inequality conditions usually being formulated for moments of physical observables. Importantly, the obtained criteria certify nonclassicality even when the involved phase-space distributions are non-negative. Moreover, we show how these inequalities are related to correlation measurements. The strength of the derived conditions is demonstrated by different examples, including squeezed states, lossy single-photon states, and even coherent states.
Journal/Review: PHYSICAL REVIEW LETTERS
Volume: 24 (13) Pages from: 133601-1 to: 133601-6
KeyWords: QUANTUM-STATE; NONCLASSICAL STATES; SQUEEZED STATES; COHERENT; ENTANGLEMENT; INFORMATION; TOMOGRAPHY; STATISTICS; OPERATORS; OPTICSDOI: 10.1103/PhysRevLett.124.133601Citations: 11data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-12-05References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here