ABSTRACT: Photon-photon interactions are fundamental to gate-based optical quantum computing and other quantum-enabled technologies. However, quantum emitter-mediated photon interactions are limited by stringent operational conditions and the available photon wavelength and bandwidth, making scaling and practical applications challenging. To overcome these limitations, it is long sought to achieve interactions between individual photons using bulk optical nonlinearity, such as chi2 and chi3. I will describe the first observation of photon-photon interaction in an integrated photonic circuit with significant chi2 nonlinearity. This resulted in quantum correlations of transported photons, including photon repulsion and attraction. These results represent a significant advance in quantum nonlinear photonics and pave the way towards realizing strongly-interacting photons in bulk nonlinear systems. Moreover, I will talk about using the integrated nonlinear photonic platform for nonlinearity-enabled quantum information processing and quantum networking.

Biography:  Kejie Fang received BS in physics from Peking University and PhD in physics from Stanford University, advised by Prof. Shanhui Fan. He then worked in Caltech as a postdoctoral researcher in Prof. Oskar Painter’s group. He is now an Assistant Professor and Y.T. Lo Faculty Fellow in the Department of Electrical and Computer Engineering and affiliated with the Department of Physics. His research focus is in quantum photonics and devices for quantum information processing and networking. He has received NSF CAREER Award and was selected for DARPA Young Faculty Award.