Quantum foundation

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.