Loophole-Free Bell Inequality Violation with Superconducting Circuits: Experiment*

To our knowledge, no loophole-free Bell tests have been performed with macroscopic degrees of freedom to date. Here we present our progress towards performing such a test with superconducting qubits separated by 30 meters of physical distance. In that setting, we attempt to close the locality, detection and freedom-of-choice loopholes and present first data. Realizing loophole-free Bell tests is a key ingredient for future applications such as device-independent quantum information processing [1, 2].

[1] R. Colbeck and R. Renner, Nature Physics 8 (2012)

[2] U. Vazirani et al., PRL 116, 089901 (2016)