Protocol for unambiguous quantum state discrimination using quantum coherence

TL;DR

This paper introduces a protocol leveraging quantum coherence to achieve unambiguous discrimination between two nonorthogonal quantum states, expanding the understanding of resources needed beyond entanglement and dissonance.

Contribution

It demonstrates that quantum coherence alone can be used for unambiguous quantum state discrimination and provides a method to quantify and optimize the required coherence.

Findings

Quantum coherence can be utilized for state discrimination.

The protocol quantifies the coherence needed for optimal discrimination.

Discussion of strategies for optimal unambiguous discrimination.

Abstract

Roa et al. showed that quantum state discrimination between two nonorthogonal quantum states does not require quantum entanglement but quantum dissonance only. We find that quantum coherence can also be utilized for unambiguous quantum state discrimination. We present a protocol and quantify the required coherence for this task. We discuss the optimal unambiguous quantum state discrimination strategy in some cases. In particular, our work illustrates an avenue to find the optimal strategy for discriminating two nonorthogonal quantum states by measuring quantum coherence.