Entanglement swapping via three-step quantum walk-like protocol

TL;DR

This paper introduces a novel entanglement swapping method using a three-step quantum walk-like protocol, replacing Bell-state measurement, enabling efficient entanglement concentration and simplifying optical quantum processing.

Contribution

It proposes a new entanglement swapping scheme based on quantum walk-like state discrimination, enhancing quantum computation dynamics and reducing optical integration complexity.

Findings

Enables entanglement swapping of unknown nonmaximally entangled states.

Outputs can be maximally entangled, facilitating entanglement concentration.

Reduces the complexity of optical quantum processing.

Abstract

We present an entanglement swapping process for unknown nonmaximally entangled photonic states, where the standard Bell-state measurement is replaced by a three-step quantum walk-like state discrimination process, i.e., the practically nontrivial coupling element of two photons is replaced by manipulating their trajectories, which will greatly enrich the dynamics of the coupling between photons in realizing quantum computation, and reduce the integration complexity of optical quantum processing. In addition, the output state can be maximally entangled, which allows for entanglement concentration as well.