Theoretical seminar | 02 September 2020

ITMO University, Ioffe Institute, Australian National University
Waveguide QED: non-Markovian subradiance and interaction-induced quantum chaos
I will discuss two problems in the field of waveguide quantum electrodynamics (QED) studying propagating photons coupled to arrays of atoms or superconducting qubits. First, I will consider a periodic Bragg-spaced array of superconducting qubits. I will demonstrate that both photon bunching and anti-bunching persist at times that greatly exceed both radiative and non-radiative lifetimes of a single qubit. The correlations become immune to non-radiative dissipation due to the Borrmann effect, that is a strongly non-Markovian collective feature of light-qubit coupling inherent to the Bragg regime. Second, I will discuss interaction-induced chaotic states for photon pairs. I will show that nonparabolicity of the polariton dispersion enables a new mechanism of quantum chaos and nonintegrability. These results provide new insights in the interplay between order, chaos and localization in many-body quantum systems.