title: Hardy's nonlocality proof using twisted photons.
abstract: Hardy's nonlocality proof is considered as "the best version of Bell's theorem". We report an experimental implementation of this by measuring the orbital angular momentum (OAM) of entangled twisted photon pairs. Two advantages arise from using twisted photons. First, the limited OAM spectrum generated by parametric down-conversion provides a natural set of OAM non-maximally entangled states with selective degrees of entanglement. Second, the measurement of any non-trivial superposition of OAM states can be conveniently done with spatial light modulators. We measure states that are defined on asymmetric OAM Bloch spheres and show results which are incompatible with local realism.
authors.affiliation: Department of Physics, Xiamen University, Xiamen 361005, China. chenlx@xmu.edu.cn
authors.forename: Lixiang
authors.initials: L
authors.lastname: Chen
authors.forename: Jacquiline
authors.initials: J
authors.lastname: Romero