Quantum correlations in prepare-and-measure scenarios and their semi-device-independent applications

TL;DR

This paper reviews how quantum correlations in prepare-and-measure scenarios enable semi-device-independent quantum communication, highlighting recent protocols and fundamental insights into quantum advantages over classical systems.

Contribution

It provides a comprehensive introduction to quantum prepare-and-measure correlations and their applications in semi-device-independent quantum information processing.

Findings

Quantum correlations enable advantages in communication tasks.

Protocols for quantum randomness certification and key distribution have been developed.

Trade-offs between security, performance, and implementation ease are explored.

Abstract

A key aspect in quantum information is to understand the advantage offered by quantum systems over classical ones in communication tasks. In recent years, a fundamental approach to this problem has been developed, focusing on quantum correlations in prepare-and-measure scenarios. Inspired by the developments in Bell nonlocality and device-independent information processing, this line of research aims to characterize the possibilities and limits of quantum systems for communication, in particular to precisely capture the advantage they offer over classical systems. In addition to fundamental insights, these ideas also underpin the concept of semi-device-independent quantum information processing. Exploring trade-offs between security, performance and ease-of-implementation, this approach opens promising directions for novel quantum information processing technologies and devices. A number of protocols and proof-of-principle demonstrations have been reported in recent years, in particular for quantum randomness certification and key distribution. Here, we provide a comprehensive introduction to quantum prepare-and-measure correlations and semi-device independent applications.