Quantum Optics Seminar: Sahand Mahmoodian, The University of Sydney

Many-body quantum optics with quantum emitters

In this talk, I will discuss two projects. In the first I will examine the use of quantum emitters for generating non-Gaussian states of light. So far, quantum emitters have mostly been used for generating individual or single entangled photons. While many-body states can be generated they usually end up being multimoded (eg superradiance). Here we show how individual quantum emitters can be interfaced with single-mode flying optical photons and be used to absorb or add a single photon to that mode. This allows building up large single-mode Fock states. I also consider interfacing few-photon states generated from this protocol with squeezing operations to generate cat states. In the second part of my talk I will outline a perturbative method we have developed for calculating three-photon transport through atomic ensembles. Atomic ensembles are usually weakly coupled to an optical mode so the coupling parameter is a good perturbation parameter. We show how this can be used to determine a hierarchy of Feynmann diagrams describing the scattering process where a leading-order diagrams can be easily computed. Our calculations allow evaluating observables such as the connected third-order intensity correlation function. The possibility of using ensembles for generating non-Gaussian states of light are discussed.