Nonlocal Interferometry Using Macroscopic Coherent States and Weak Nonlinearities

TL;DR

This paper presents a method for nonlocal interferometry with macroscopic coherent states, leveraging weak nonlinearities to generate entanglement, which remains robust against photon loss and allows Bell inequality violation over long distances.

Contribution

It introduces a novel approach to nonlocal interferometry using phase-entangled macroscopic states and weak nonlinearities, demonstrating robustness and long-distance Bell inequality violation.

Findings

Entanglement can be generated with weak nonlinearities.

Bell's inequality can be violated over large distances.

Robustness against photon loss is achieved.

Abstract

A method for performing nonlocal interferometry using phase-entangled macroscopic coherent states is described. The required entanglement can be generated using weak nonlinearities while Bell's inequality can be violated using single photons as a probe. The entanglement is relatively robust against photon loss and Bell's inequality can be violated over a relatively large distance in optical fibers despite the fact that a large number of photons are absorbed in the process.