Communication Through a Quantum Link

TL;DR

This paper demonstrates how a chain of interacting spins can act as a quantum link enabling perfect quantum communication between distant parties, by modeling it as a correlated quantum channel with finite memory.

Contribution

It introduces a protocol for perfect quantum information transmission through a quantum link modeled as a finite memory quantum channel, connecting physical systems to quantum information theory.

Findings

Quantum link modeled as correlated quantum channel with finite memory

Protocol achieves perfect quantum information transmission

Repetition without resetting maintains channel correlations

Abstract

A chain of interacting spin behaves like a quantum mediator (quantum link) which allows two distant parties that control the ends of the chain to exchange quantum messages. We show that over repeated uses without resetting the study of a quantum link can be connected to correlated quantum channels with finite dimensional environment (finite memory quantum channel). Then, using coding arguments for such kind of channels and results on mixing channels we present a protocol that allows us to achieve perfect information transmission through a quantum link.