Device-Independent Bounds on Detection Efficiency

TL;DR

This paper develops a method to establish lower bounds on detector efficiency in quantum experiments by deriving Bell inequalities that are immune to the detection loophole, ensuring reliable quantum security.

Contribution

It introduces a systematic technique to derive detection-loophole-free Bell inequalities solely from observed measurement data.

Findings

Derived Bell inequalities free from the detection loophole.

Provided lower bounds on detector efficiency based on observed data.

Validated the approach with theoretical analysis.

Abstract

In many quantum information applications, a minimum detection efficiency must be exceeded to ensure success. Protocols depending on the violation of a Bell inequality, for instance, may be subject to the so-called detection loophole: imperfect detectors may yield spurious violations, which consequently cannot be used to ensure, say, quantum cryptographic security. Hence, we investigate the possibility of giving lower bounds on detector efficiency even if an adversary has full control over both the source and the detectors. To this end, we present a technique to systematically derive Bell inequalities free from the detection loophole using only the observed measurements statistics. The violation of these inequalities certifies that the detectors used exceed a certain minimal efficiency.