Generation and application of high-quality single photons - Xianxin Guo

Photon-atom interaction lies at the heart of quantum optics and quantum information processing. Working with atomic ensembles and making use of the electromagnetically induced transparency (EIT) effect, the photon-atom interaction efficiency can be significantly enhanced for exploration of unconventional phenomana. In this talk, I will report generation and application of high-quality heralded single photons from EIT-assisted four-wave mixing (FWM) in cold atomic ensembles and a hot atomic vapor cell. These photon pairs are narrowband, spectrally bright and nearly Fourier-transform limited. With these narrowband photon pairs at hand, frequency-bin entanglement can be created and tested through the Bell-CHSH inequality in a time-resolved mode. Such unique entangled photon pairs may be utilized for quantum metrology and quantum information processing. On the other hand, increasing the FWM parametric gain leads to transition from the single photon quantum regime to mirrorless optical parametric oscillation (MOPO) regime, enabling different physics such as quantum squeezing to be explored on this platform.