Cavity QED Lattices: A platform to study many-body physics with photons

Dr. Hakan Tureci, Princeton University

Goergen 101

Abstract

Quantum matter coupled to enhanced optical fields in confined geometries such as resonators and waveguides offer a promising platform to study emergent phenomena far-from-equilibrium. In my talk I will discuss our recent efforts at understanding what a quantum phase transition of photons may look like in a lattice of Cavity Quantum Electrodynamics systems, where photons become itinerant. Surprisingly this has lead us back to the very origin of Quantum Electrodynamics and the Quantum Theory, namely to Planck and Einstein's theory of thermal cavity radiation. We find a modification to the Planck-Einstein theory due to the backaction from (material) oscillators and show that a Cavity QED network displays an instability towards a ferroelectric phase when light-matter coupling is sufficiently increased. The true potential of coupled light-matter systems is however unleashed in driven Cavity QED networks. I will discuss a general method to use photon-mediated interactions between qubits to drive them to a long-distance entangled state with an arbitrarily long lifetime. We find that photon-mediated interactions provide a highly versatile toolbox to engineer the unitary and dissipative dynamics of spatially separated qubits, with important implications for dissipative stabilization of pure many-body states of qubits.

Location: Goergen 101

Refreshments will be served.