Friday 03 Mar 2023: Quantum optics and quantum thermodynamics with semiconductor quantum dots
Pascale Senellart-Mardon - Université Paris-Saclay
Newman Red 12:30-13:30
Semiconductor quantum dots have emerged as very interesting artificial atoms. When inserted in optical microcavities, their interaction with their solid-state environment can be reduced, and they can emit highly indistinguishable single photons . Taking advantage of all the tools of semiconductor nano-processing, our devices have come closer and closer to the text-book atom-photon interface and allow to explore fundamental aspects of light emission process.
In this talk, I will discuss how we recently revisited the process of spontaneous emission. We first demonstrated that the quantum coherence imprinted at the atomic level is transferred to the light field in the spontaneous emission process. We generate light in pure quantum superpositions of 0,1 or even 2 photons . We more recently demonstrated that one can perform operation on a single atom that is undergoing spontaneous emission and generate photon-number entanglement . Finally, we used our quantum dot platform to explore the energy exchanges that take place during quantum light generation and quantum interferences, two key building blocks for optical quantum technologies. We proposed an experimental protocol that allows measuring the work transferred from the quantum dot to the electromagnetic field during spontaneous emission. At low temperatures, the observed work transfer is close to the theoretical upper bound, a value that is degraded at higher temperatures when the quantum dot is subject to pure dephasing. We then studied how to discharge this optical quantum battery onto a classical field through a quantum interference and identified the conditions for maximal work transfer .
 P. Senellart, G. Solomon and A. White, Nature nanotechnology 12, 1026 (2017)
 C. Anton, et al, Nature Photonics 13, 803–808 (2019)
 S. Wein et al, Nature Photonics 16 (5), 374-379 (2022)
 I. Maillette de Buy Wenniger et al, arXiv:2202.01109