Quantum state discrimination and its applications

TL;DR

This paper reviews quantum state discrimination, a fundamental process in quantum information, highlighting recent progress, applications, and its deep connections to quantum foundations and cryptography.

Contribution

It provides a comprehensive overview of recent advances in quantum state discrimination and explores its applications in quantum information processing and foundational principles.

Findings

Summarizes recent progress in quantum state discrimination techniques.

Highlights applications in quantum cryptography and information theory.

Connects quantum state discrimination to fundamental physical principles.

Abstract

Quantum state discrimination underlies various applications in quantum information processing tasks. It essentially describes the distinguishability of quantum systems in different states, and the general process of extracting classical information from quantum systems. It is also useful in quantum information applications, such as the characterisation of mutual information in cryptographic protocols, or as a technique to derive fundamental theorems in quantum foundations. It has deep connections to physical principles such as relativistic causality. Quantum state discrimination traces a long history of several decades, starting with the early attempts to formalise information processing of physical systems such as optical communication with photons. Nevertheless, in most cases, optimal strategies of quantum state discrimination remain unsolved, and related applications are valid in some limited cases only. The present review aims to provide an overview on quantum state discrimination, covering some recent progress, and addressing applications in some selected topics. This review serves to strengthen the link between results in quantum state discrimination and quantum information applications, by showing the ways in which the fundamental results are exploited in applications and vice versa.