Quantum-state transfer via resonant tunnelling through local field induced barriers

TL;DR

This paper demonstrates a method for high-fidelity quantum state transfer in a spin chain using local magnetic fields to create barriers, enabling efficient transfer over longer distances and potential entanglement distribution.

Contribution

It introduces a novel approach of using local field-induced barriers to facilitate quantum state transfer in spin chains, enhancing transfer quality at longer distances.

Findings

High-quality quantum state transfer achieved with local magnetic fields.

Bi-localized eigenstates enable efficient edge-to-edge transfer.

Method allows transfer of entangled qubit pairs across the chain.

Abstract

Efficient quantum-state transfer is achieved in a uniformly coupled spin-1/2 chain, with open boundaries, by application of local magnetic fields on the second and last-but-one spins, respectively. These effective \textit{barriers} induce appearance of two eigenstates, bi-localized at the edges of the chain, which allow a high quality transfer also at relatively long distances. The same mechanism may be used to send an entire e-bit (e.g., an entangled qubit pair) from one to the other end of the chain.