Intrinsic coherence in assisted sub-state discrimination

TL;DR

This paper investigates how intrinsic coherence affects the success of assisted sub-state discrimination of entangled qubits, revealing that initial coherence enhances success probability without extra coherence, and analyzing coherence transformations during the process.

Contribution

It introduces a detailed analysis of intrinsic coherence in assisted state discrimination, highlighting its role and transformations, and connects this to probabilistic teleportation protocols.

Findings

Initial intrinsic coherence improves discrimination success

Transformations among coherence contributions are essential

Entanglement reduces the reliance on ancilla coherence

Abstract

We study intrinsic coherence in the tripartite process to unambiguously discriminate two nonorthogonal states of a qubit, entangled with another one, and assisted by an auxiliary system. The optimal success probability is found to be benefited by initial intrinsic coherence, but no extra one is required. The transformations among different contributions of intrinsic coherence are necessary in this procedure, which increase with the overlap between the states to recognize. Such state discrimination is a key step of the probabilistic teleportation protocol. Entanglement of the quantum channel decreases the coherence characterizing the reliance on an ancilla.