Indistinguishable photon pairs and their quantum interference is a fundamental resource enabling many quantum applications such as quantum teleportation, quantum metrology, quantum communications and quantum computing. There is a growing need to generate these photon sources on-chip to create the next-generation integrated nano-photonic devices. Photon pairs are commonly produced using spontaneous parametric down-conversion (SPDC) or spontaneous-four wave mixing(SFWM). On-chip photon pairs produced through SFWM have an added advantage over SPDC of being easily scalable and not requiring special materials. However, disorder during fabrication processes changes the device functionality and makes the scalability of these devices ineffective. One prominent solution to the problem is to use topological edge states which were shown to be robust against fabrication-induced disorder.
In this work, we report the generation of indistinguishable photon pairs in an anomalous quantum Hall device using a dual-pump SFWM (DP-SFWM) process. We show that the linear dispersion of the edge states provides an efficient phase matching condition for DP-SFWM and produces maximum output spectral correlations in the edge band. The linear dispersion also make it possible to tune the bandwidth of the generated photons by changing the pump frequencies. Finally, we verify the indistinguishably of photons using Hong-Ou-Mandel (HOM) experiment and show that the generated photons are energy time-entangled. This work allows exploration of a robust tunable quantum sources on-chip which would be helpful in many applications of quantum information.
(pizza and drinks served 10 min. before talk)