Sequential State Discrimination and Requirement of Quantum Dissonance

Abstract

We study the procedure for sequential unambiguous state discrimination. A qubit is prepared in one of two possible states, and measured by two observers Bob and Charlie sequentially. A necessary condition for the state to be unambiguously discriminated by Charlie is the absence of entanglement between the principal qubit, prepared by Alice, and Bob's auxiliary system. In general, the procedure for both Bob and Charlie to recognize between two nonorthogonal states conclusively relies on the availability of quantum discord which is precisely the quantum dissonance when the entanglement is absent. In Bob's measurement, the left discord is positively correlated with the information extracted by Bob, and the right discord enhances the information left to Charlie. When their product achieves its maximum the probability for both Bob and Charlie to identify the state achieves its optimal value.

4.5 pages, 3 figures

References in corpus (4)

• Quantum discord and the power of one qubit
• Necessary and sufficient condition for non-zero quantum discord
• Experimental quantum computing without entanglement
• Optimal Unambiguous Discrimination of Quantum States

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• Local Quantum Uncertainty in Two-Qubit Separable States: A Case Study
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• Universal quantum correlation close to quantum critical phenomena
• Assisted optimal state discrimination without entanglement
• Discriminating bipartite mixed states by local operations
• Discrimination of Coherent States via Atom-Field Interaction without Rotation Wave Approximation
• Unambiguous state discrimination with intrinsic coherence
• Conclusive discrimination by $N$ sequential receivers between $r\ge 2$ arbitrary quantum states
• Distributing quantum correlations through local operations and classical resources
• Generating quantum dissonance via local operations
• Quantum State Discrimination via Repeated Measurements and the Rule of Three
• Unbounded entanglement-sustaining sequential local quantum state discrimination