Realistic loophole-free Bell test with atom-photon entanglement

TL;DR

This paper proposes an experimental setup for a loophole-free Bell test using atom-photon entanglement, achieving significant violation of Bell inequality under realistic conditions, advancing device-independent quantum technologies.

Contribution

It introduces a practical atom-photon entanglement scheme that closes major loopholes in Bell tests with current experimental capabilities.

Findings

Achieves Bell inequality violation with realistic detection efficiencies.

Remains robust under typical propagation losses.

Proposes a feasible setup for loophole-free Bell tests.

Abstract

The establishment of nonlocal correlations, obtained through the violation of a Bell inequality, is not only important from a fundamental point of view, but constitutes the basis for device-independent quantum information technologies. Although several nonlocality tests have been performed so far, all of them suffered from either the locality or the detection loopholes. Recent studies have suggested that the use of atom-photon entanglement can lead to Bell inequality violations with moderate transmission and detection efficiencies. In this paper we propose an experimental setup realizing a simple atom-photon entangled state that, under realistic experimental parameters available to date, achieves a significant violation of the Clauser-Horn-Shimony-Holt inequality. Most importantly, the violation remains when considering typical detection efficiencies and losses due to required propagation distances.