Violation of Bell's inequalities with pre-amplified homodyne detection

TL;DR

This paper demonstrates that probabilistic noiseless amplification enhances Bell inequality tests with entangled coherent states, reducing the required amplitude for nonlocality detection even with detection inefficiencies.

Contribution

It introduces the use of noiseless amplification within Bell tests, showing significant advantages in detecting quantum nonlocality with lower amplitude thresholds.

Findings

Amplification reduces the amplitude threshold for Bell violation.

The advantage persists despite detection inefficiencies.

Supports noiseless amplification as a tool for quantum information processing.

Abstract

We show that the use of probabilistic noiseless amplification in entangled coherent state-based schemes for the test of quantum non locality provides substantial advantages. The threshold amplitude to falsify a Bell-CHSH non locality test, in fact, is significantly reduced when amplification is embedded into the test itself. Such a beneficial effect holds also in the presence of detection-inefficiency. Our study helps in affirming noiseless amplification as a valuable tool for coherent information processing and the generation of strongly non classical states of bosonic systems.