2015/01/31 by Diego Paiva Pires, Lucas C. Céleri, Diogo O. Soares-Pinto · 1 citation
Computer Science · Physics and Astronomy · #Coherence (philosophical gambling strategy) #Mathematical analysis #Measure (data warehouse) #Open quantum system #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum discord #Quantum mechanics #Quantum optics and atomic interactions #Statistical physics #Theoretical physics #Upper and lower bounds #quant-ph
paper · pdf · doi:10.1103/physreva.91.042330
published as Phys. Rev. A 91, 042330 (2015) · 9 pages, REVTeX 4-1, close to published version
arxiv created 2015/04/23 · openalex publication_date 2015/04/23 · arxiv updated 2015/04/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Nowadays, geometric tools are being used to treat a huge class of problems of quantum information science. By understanding the interplay between the geometry of the state space and information-theoretic quantities, it is possible to obtain less trivial and more robust physical constraints on quantum systems. Here we establish a geometric lower bound for the Wigner-Yanase skew information (WYSI), a well-known information-theoretic quantity recently recognized as a proper quantum coherence measure. In the case of a mixed state evolving under unitary dynamics generated by a given observable, the WYSI between the state and the observable is bounded from below by the rate of change of the state's statistical distinguishability from its initial value. Our result shows that, since WYSI fits in the class of Petz's metrics, this lower bound is the change rate of its respective geodesic distance on quantum state space. The geometric approach is advantageous because it raises several physical interpretations of this inequality under the same theoretical umbrella.