Researchers at NIST and JQI have developed a high-efficiency photon source that could bring a definitive test of Bell’s inequality closer to reality. The source, which produces paired photons with 84% efficiency, represents a significant step towards closing the “detection loophole” in Bell tests. This would allow for a loophole-free test of quantum theory, which could resolve long-standing debates about the nature of quantum entanglement.
The experiment aims to demonstrate that entangled photons cannot be explained by hidden variables, as proposed by some interpretations of quantum mechanics. Current experiments have violated Bell’s inequality, but critics argue that imperfections in the experimental setup could still allow for hidden variables to explain the results.
The new photon source, combined with a 99% efficient detector developed by NIST physicist Sae Woo Nam, brings the possibility of a loophole-free Bell test closer. Such a test would provide strong evidence for the validity of quantum mechanics and could have important implications for quantum cryptography and random number generation.
The researchers emphasize that while the physics community is confident in the predictions of quantum theory, the security community requires absolute proof that quantum processes are truly random and not subject to hidden influences. The development of this high-efficiency photon source is a crucial step towards providing that proof.
Keywords: photons, entangled, efficiency, loophole, quantum
