2021/05/31 by Maria Poxleitner, Haye Hinrichsen
Computer Science · Mathematics · Physics and Astronomy · #Algorithm #Gaussian #Gaussian noise #Isotropy #Mathematics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum entanglement #Quantum mechanics #State (computer science) #Statistical physics #quant-ph
paper · pdf · doi:10.1103/physreva.104.032423
published as Phys. Rev. A 104, 032423 (2021) · 12 pages, 5 figures; modified abstract, extended and additional paragraphs, revised figures, added references
arxiv created 2021/09/16 · openalex publication_date 2021/09/28 · arxiv updated 2021/10/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Inspired by the definition of the non-Gaussian two-parametric continuous-variable analog of an isotropic state introduced by Mi\ifmmode \checks\else \vs\fita et al. [Phys. Rev. A 65, 062315 (2002)], we propose to take the Gaussian part of this state as an independent state by itself, which yields a simple, but with respect to the correlation structure interesting, example of a two-mode Gaussian analog of an isotropic state. Unlike conventional isotropic states which are defined as a convex combination of a thermal and an entangled density operator, the Gaussian version studied here is defined by a convex combination of the corresponding covariance matrices and can be understood as an entangled pure state with additional Gaussian noise controlled by a mixing probability. Using various entanglement criteria and measures, we study the nonclassical correlations contained in this state. Unlike the previously studied non-Gaussian two-parametric isotropic state, the Gaussian state considered here features a finite threshold in the parameter space where entanglement sets in. In particular, it turns out that it exhibits an analogous phenomenology as the finite-dimensional two-qubit isotropic state.