Superradiance, sub-radiance and non-Hermitian physics

Light-coupled arrays of emitters form an inherently open system due to the possibility of spontaneous photon emission into the far field. Interestingly, the decay rate of collective eigenmodes within these emitter arrays can be either enhanced (for superradiant modes) or suppressed (for subradiant modes) when compared to the decay rate of an individual emitter. The development of such collective modes can be described by effective non-Hermitian Hamiltonians, known for their unique properties.

Our initial research focused on the phenomena of super- and sub-radiance within periodic and quasiperiodic arrays of light-coupled semiconductor quantum wells. Within these arrays, we observed that collective enhancement and suppression of emission could occur depending on whether the inter-well spacings were in tune or out of tune with the Bragg condition at the frequency of the exciton inside the quantum wells.

More recently, our research interests have shifted to artificial quantum systems, specifically, arrays of superconducting qubits. In the weak excitation regime these systems share a lot of similarities with the quantum well arrays. However, in a highly excited or driven regime, the lifetime of quantum correlations becomes highly sensitive to the nuances of many-body interactions within the array. This research aims to unlock deeper understanding of these quantum interactions and their potential implications for quantum technologies.

Selected publications



Qubit arrays

Quantum well arrays

In collaboration with experimentalists

Superconducting qubits

Semiconductor quantum wells