Quantum nonlocality without entanglement and state discrimination measures
Abstract
An ensemble of product states is said to exhibit “quantum nonlocality without entanglement” if it cannot be optimally discriminated using local operations and classical communication (LOCC). We show that this property can depend on the chosen discrimination measure. Specifically, we construct a family of ensembles, each consisting of six linearly independent, equally probable bipartite product states, for which LOCC fails to achieve optimal minimum-error discrimination but succeeds in achieving optimal unambiguous discrimination. We further extend our construction to multipartite systems and provide strong numerical evidence that a similar separation between local and global optima is present for minimum-error discrimination, but not for unambiguous discrimination.
Fields of Study & Subjects
Quantum Mechanics and Applications
Quantum Information and Cryptography
Publication details
- Journal / source
- Quantum
- Publisher
- Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften
- Volume
- 10
- Pages
- 2174–2174
- Publication date
- 23 July 2026
- Language
- EN