Inter and intra particle entanglement as a resource for integrated quantum photonics

Correlated photon pairs are a crucial resource of many quantum photonic systems. This quantum-correlated light can be produced by nonlinear processes like spontaneous parametric downconversion (SPDC) or spontaneous four-wave mixing (SFWM) and can be used in various applications exploiting quantum interference: quantum teleportation, quantum simulation and quantum computing rely on the interference of identical photons. Quantum entanglement can be made between two distinct photons (non-locality) or between two degrees of freedom of the same photon (contextuality). Here I will review few integrated quantum photonic circuits based on inter or intra photon entanglement that implement quantum random number generators operated by a LED, quantum ghost spectroscopy devices for MIR absorption, on-chip undetected photon quantum intereference and, finally, hearlded single photon sources for quantum simulator and quantum machine learning applications.

The work is supported by Q@TN, a joint laboratory between University of Trento, Bruno Kessler Foundation, INFN and CNR through the financial contribution of Provincia Autonoma of Trento.