Remote quantum gates mediated by spin chains

TL;DR

This paper shows how spin chains designed for perfect quantum state transfer can also be used to generate remote quantum gates, enabling entanglement and universality independent of chain length.

Contribution

It introduces a method to use spin chains for remote quantum gate generation, expanding their application beyond state transfer.

Findings

Spin chains can generate maximally-entangling quantum gates.

The gates are universal and independent of chain length.

The system naturally evolves to produce these gates.

Abstract

There has been much recent study on the application of spin chains to quantum state transfer and communication. Here we demonstrate that spin chains set up for perfect quantum state transfer can be utilised to generate remote quantum gates, between spin qubits injected at the ends of the chain. The natural evolution of the system across different excitation number sectors generates a maximally-entangling and universal gate between the injected qubits, independent of the length of the chain.