Abstract:
Control and manipulation of the collective radiative states of atomic systems could bring new opportunities for quantum many-body physics and quantum networks. In this talk, I will discuss our recent investigation on “selective radiance,” a phenomenon in which an atomic excitation couples to a specific photonic channel with collective enhancement (called ‘superradiance’) but to all other channels with suppression (‘subradiance’). Following our recent experimental realization of cold atom trapping on a nanophotonic microring resonator, we study how a dense atomic ensemble collectively couples to a whispering-gallery-mode in the resonator and to other free space modes. I will discuss the decay dynamics of an atomic ensemble following long and short excitation pulses, with the former driving the system into a steady state and the latter into a so-called timed-Dicke state. I will discuss the potential of our platform to realize selective radiance in an atom array and explore collective quantum optics with trapped atoms coupled to nanophotonic circuits.

Bio. Dr. Hung received his PhD in Physics at the University of Chicago in 2011, where he developed an in-situ microscopy technique on two-dimensional atomic quantum gases to study quantum phase transitions. Before joining Purdue in 2015 as a faculty member, he held a postdoctoral fellowship at the California Institute of Technology and developed one of the first photonic crystal atom-photon interfaces for quantum optics. His research directions at Purdue University span from studying out-of-equilibrium many-body physics using atomic quantum gases to interfacing ultracold atoms with nanophotonic circuits for quantum optics and many-body physics with photon-mediated long-range interactions. He is a recipient of the AFOSR Young Investigator Award and the NSF CAREER award.