Condition for unambiguous state discrimination using local operations and classical communication

A class of unambiguous state discrimination problems achievable by separable measurements but impossible by local operations and classical communication

We consider an infinite class of unambiguous quantum state discrimination problems on multipartite systems, described by Hilbert space H, of any number of parties. Restricting consideration to measurements that act only on H, we find the optimal global measurement for each element of this class, achieving the maximum possible success probability of 1/2 in all cases. This measurement turns out t...

When do Local Operations and Classical Communication Suffice for Optimal Quantum State Discrimination?

In this talk we consider when an ensemble of states can be optimally distinguished by local operations and classical communication (LOCC). It is shown that almost all two-qubit ensembles consisting of three pure states cannot be optimally discriminated using LOCC. This is surprising since any two pure states can be distinguished optimally by LOCC. Additionally, we prove an easy sufficient condi...

Necessary Condition for Local Quantum Operations and Classical Communication with Extensive Violation by Separable Operations

Extended Necessary Condition for Local Operations and Classical Communication: Tight Bound for All Measurements

Discrimination of two-qubit unitaries via local operations and classical communication.

Distinguishability is a fundamental and operational measure generally connected to information applications. In quantum information theory, from the postulates of quantum mechanics it often has an intrinsic limitation, which then dictates and also characterises capabilities of related information tasks. In this work, we consider discrimination between bipartite two-qubit unitary transformations...