Advanced quantum state engineering with Pockels nonlinear integrated optics

Abstract

Photons play a critical role in future quantum technology, due to its indispensable function as quantum information carrier over long distances. The efficient generation of quantum states is the foundation of quantum photonic technology. In particular, advanced quantum states beyond single-photon pairs are required to meet the rapid development of quantum communication and sensing systems. While integrated photonic circuits provide the unprecedented power to realize complex photon control with minimized structures, most materials used in integrated photonic circuits lack the preferred second-order optical nonlinearity, which limits photon control functionalities and power efficiency. In this talk, I will present our effort in developing advanced photonic states using integrated photonics with second-order nonlinearity. We will start with the first generation of squeezed light on integrated photonic platforms using parametric down-conversion. Then we will focus on the first demonstration of reconfigurable high-dimensional hyper-entanglement. This is achieved through the parallel processing of quantum frequency combs in the path domain. Cavity-enhanced parametric down-conversion with Sagnac configuration is implemented to ensure the spectral indistinguishability. Simultaneous entanglement in path and frequency is realized. On-chip reconfiguration of the entanglement structure in the path domain is also demonstrated. We further present quantum interference in both entanglement degrees of freedom with high visibility.