Alladi Ramakrishnan Hall

Cooperative Effects in Closely Packed Quantum Emitters with Collective Dephasing

B. Prasanna Venkatesh

Institute for Quantum Optics and Quantum Information, Innsbruck

The main topic of the talk will be a recent work [1], where we showed that the dipole force on a closely packed ensemble of strongly driven two-level quantum emitters, which collectively dephase, is enhanced in comparison to the dipole force on an independent non-interacting ensemble. Such a result is intriguing since in a closely packed ensemble of quantum emitters cooperative effects are typically suppressed due to the dephasing induced by the dipole-dipole interactions. In contrast we show that by adding sufficiently strong collective dephasing cooperative effects can be restored. Our results are relevant to solid-state systems with embedded quantum emitters such as colour centers in diamond and superconducting qubits in microwave cavities and waveguides. More generally such schemes enable the strong, controlled coupling of macroscopic bodies to laser light with applications in fundamental quantum mechanics as well as quantum information processing.
In the last part of the talk, I will provide an overview of the other main directions of research that I have pursued (ultracold atoms in cavities and quantum thermodynamics) as well as highlight future directions for our research program.

[1]. B. Prasanna Venkatesh, M. L. Juan, and O. Romero-Isart, Phys. Rev. Lett.120, 033602 (2018)