Experimental post-selection loophole-free time-bin and energy-time nonlocality with integrated photonics

Abstract

Time-bin (TB) and energy-time (ET) entanglements are crucial resources for long-distance quantum information processing. However, their standard implementations suffer from the so-called post-selection loophole that allows for classical simulation and thus prevents quantum advantage. The post-selection loophole has been addressed in proof-of-principle experiments. An open problem though is to close it in real-life applications based on integrated technologies. This is especially important since, so far, all integrated sources of TB and ET entanglements suffer from the post-selection loophole. Here, we report post-selection loophole-free certification of TB or ET entanglement in integrated technologies, by implementing in a silicon nitride chip the “hug” scheme [ Phys. Rev. Lett. 102 , 040401 ( 2009 ) PRLTAO 0031-9007 10.1103/PhysRevLett.102.040401 ] and certifying genuine TB entanglement through the violation of a Bell inequality.