The foundation of quantum mechanics has been challenged just after it was discovered. Albert Einstein believed in a superior local hidden variable theorem. In 1960s, John Bell proposed the an inequality (called as Bell inequality later), which provided an experimental way to test the quantum foundation. In the past fifty years, tremendous experiments has been implemented to test the Bell inequality and all support quantum mechanics. However, loopholes may exist in all these experiment, the local hidden variable theorem cannot be fully excluded. There are three main types of loopholes, locality loophole, detection loophole and freedom-of-choice loophole.
In this project, we are aiming at closing all the loopholes in an experiment. We develop high efficient entanglement photon source from spontaneous parametric down-conversion, high speed timing synchronization technology and high speed random number generation. When implementing the Bell inequality experiment, we can also test the speed of quantum nonlocal correlation, quantum nonlocality under large scale, quantum sterring，randomness of human free will and comic ray emission. Moreover, loophole free Bell test is also an important resource for device independent quantum key distribution and quantum random number generation.
- [PhysicsWorld] Particle-free quantum communication is achieved in the lab
- The BIG Bell Test: Quantum Physics Entangled with Human Randomness
- Experimental measurement-dependent local Bell test with human free will. Physical Review A 99, 022115 (2019).
- Bell Test over Extremely High-Loss Channels: Towards Distributing Entangled Photon Pairs between Earth and the Moon. Physical Review Letters 120, 140405 (2018).
- Device-independent quantum random-number generation. Nature 562, 548 (2018).
- High-Speed Device-Independent Quantum Random Number Generation without a Detection Loophole. Physical Review Letters 120, 010503 (2018).
- Phase amplification in optical interferometry with weak measurement. Physical Review A 97, 033851 (2018).
- Test of Local Realism into the Past without Detection and Locality Loopholes. Physical Review Letters 121, 080404 (2018).
- Direct counterfactual communication via quantum Zeno effect. Proceedings of the National Academy of Sciences of the United States of America 114, 4920-4924 (2017).
- Random Number Generation with Cosmic Photons. Physical Review Letters 118, 140402 (2017).
- Genuine High-Order Einstein-Podolsky-Rosen Steering. Physical Review Letters 115, 010402 (2015).
- Experimental Unconditionally Secure Bit Commitment. Physical Review Letters 112, 010504 (2014).