A photonic which-path entangler based on longitudinal cavity-qubit coupling

TL;DR

This paper introduces a method using modulated longitudinal cavity-qubit coupling to create qubit-which-path entanglement, enabling long-range multipartite entanglement distribution in quantum networks without single-photon sources or detectors.

Contribution

The paper presents a novel approach to generate qubit-which-path entanglement via longitudinal cavity-qubit coupling modulation, facilitating quantum network entanglement distribution.

Findings

Enables control of photon path conditioned on qubit state

Allows long-range multipartite entanglement generation

Does not require single-photon sources or detectors

Abstract

We show that a modulated longitudinal cavity-qubit coupling can be used to control the path taken by a multiphoton coherent-state wavepacket conditioned on the state of a qubit, resulting in a qubit-which-path (QWP) entangled state. QWP states can generate long-range multipartite entanglement using strategies for interfacing discrete- and continuous-variable degrees-of-freedom. Using the approach presented here, entanglement can be distributed in a quantum network without the need for single-photon sources or detectors.