Entanglement-assisted entanglement purification

TL;DR

This paper introduces a new class of entanglement-assisted purification protocols that efficiently produce high-fidelity entangled states from noisy ensembles, improving yield and fidelity for quantum communication and computation.

Contribution

It proposes novel protocols utilizing high-dimensional auxiliary entanglement to enhance entanglement purification efficiency and fidelity, especially for decay noise and moderate-sized ensembles.

Findings

Achieves higher yield and fidelity compared to previous methods.

Effectively handles arbitrary errors, optimized for few errors.

Applicable to near-term quantum devices with moderate ensemble sizes.

Abstract

The efficient generation of high-fidelity entangled states is the key element for long-distance quantum communication, quantum computation and other quantum technologies, and at the same time the most resource-consuming part in many schemes. We present a new class of entanglement-assisted entanglement purification protocols that can generate high-fidelity entanglement from noisy, finite-size ensembles with improved yield and fidelity as compared to previous approaches. The scheme utilizes high-dimensional auxiliary entanglement to perform entangling non-local measurements and determine the number and positions of errors in an ensemble in a controlled and efficient way, without disturbing the entanglement of good pairs. Our protocols can deal with arbitrary errors, but are best suited for few errors, and work particularly well for decay noise. Our methods are applicable to moderate sized ensembles, as will be important for near term quantum devices.