{"id":"doi:10.1038/s41586-023-05885-0","kind":"article","title":"Loophole-free Bell inequality violation with superconducting circuits","authors":["Simon Storz","Josua Schär","Anatoly Kulikov","Paul Magnard","Philipp Kurpiers","Janis Lütolf","T. Walter","Adrian Copetudo","Kevin Reuer","Abdulkadir Akın","Jean-Claude Besse","Mihai S. Gabureac","Graham J. Norris","Andrés Rosario Hamann","Ferran Martin Ciurana","José Martinez","Waldimar Amaya","Morgan W. Mitchell","Carlos Abellán","Jean-Daniel Bancal","Nicolas Sangouard","Baptiste Royer","Alexandre Blais","Andreas J. Wallraff"],"author_count":24,"year":2023,"published":"2023-05-10","venue":"Nature","cited_by":219,"doi":"10.1038/s41586-023-05885-0","arxiv_id":null,"nct_id":null,"source_url":"https://doi.org/10.1038/s41586-023-05885-0","archive_url":"https://space-kitty.com/papers/doi:10.1038/s41586-023-05885-0","updated":null,"pmid":"37165240","pmcid":null,"openalex_id":"W4376130945","pdf_url":"https://www.nature.com/articles/s41586-023-05885-0.pdf","abstract":"Abstract Superposition, entanglement and non-locality constitute fundamental features of quantum physics. The fact that quantum physics does not follow the principle of local causality1–3 can be experimentally demonstrated in Bell tests4 performed on pairs of spatially separated, entangled quantum systems. Although Bell tests, which are widely regarded as a litmus test of quantum physics, have been explored using a broad range of quantum systems over the past 50 years, only relatively recently have experiments free of so-called loopholes5 succeeded. Such experiments have been performed with spins in nitrogen–vacancy centres6, optical photons7–9 and neutral atoms10. Here we demonstrate a loophole-free violation of Bell’s inequality with superconducting circuits, which are a prime contender for realizing quantum computing technology11. To evaluate a Clauser–Horne–Shimony–Holt-type Bell inequality4, we deterministically entangle a pair of qubits12 and perform fast and high-fidelity measurements13 along randomly chosen bases on the qubits connected through a cryogenic link14 spanning a distance of 30 metres. Evaluating more than 1 million experimental trials, we find an average S value of 2.0747 ± 0.0033, violating Bell’s inequality with a P value smaller than 10−108. Our work demonstrates that non-locality is a viable new resource in quantum information technology realized with superconducting circuits with potential applications in quantum communication, quantum computing and fundamental physics15.","abstract_license":"CC-BY (publisher license, via OpenAlex)","license":"cc-by","is_open_access":true,"retracted":false,"peer_reviewed":null,"categories":["Quantum Information and Cryptography"],"details":null,"provenance":"openalex","attribution":"Abstract of \"Loophole-free Bell inequality violation with superconducting circuits\" by Simon Storz, Josua Schär, Anatoly Kulikov et al., https://doi.org/10.1038/s41586-023-05885-0, used under its Creative Commons Attribution license (CC-BY); markup removed, otherwise unmodified.","topics":[{"slug":"quantum-foundations","name":"Quantum Foundations","domain_slug":"physics"}],"cited_in_dossiers":[]}