Entanglement Distillation using the Exchange Interaction

TL;DR

This paper introduces entanglement distillation protocols utilizing exchange interaction-based qubit couplings, improving the generation of high-fidelity entangled pairs for quantum repeaters.

Contribution

It presents novel entanglement distillation protocols based on exchange interactions, including asymmetric bilateral and three-pair isotropic exchange methods.

Findings

Protocols effectively increase entanglement fidelity.

Tradeoff analysis between fidelity improvement and success probability.

Protocols applicable to quantum repeater architectures.

Abstract

A key ingredient of quantum repeaters is entanglement distillation, i.e., the generation of high-fidelity entangled qubits from a larger set of pairs with lower fidelity. Here, we present entanglement distillation protocols based on qubit couplings that originate from exchange interaction. First, we make use of asymmetric bilateral two-qubit operations generated from anisotropic exchange interaction and show how to distill entanglement using two input pairs. We furthermore consider the case of three input pairs coupled through isotropic exchange. Here, we characterize a set of protocols which are optimizing the tradeoff between the fidelity increase and the probability of a successful run.