Theory Seminar: Quantum Material’s Control and Quantum Nonlinear Optics in Cavity QED

Francesco Piazza (Max Planck Institute for the Physics of Complex Systems in Dresden)
 

Francesco Piazza (Max Planck Institute for the Physics of Complex Systems in Dresden)
Group seminar via zoom
Wed, 13 April 2022, 10:30 am (MEZ)

Abstract:

The interaction between light and matter plays a prominent role both in condensed-matter physics and quantum
optics, and underlies many important technologies. For instance, the use of laser light to control collective
phenomena in materials is one of the currently most proficient areas of research in solid-state physics, and also
essential in the realisation of synthetic matter made of ultracold atoms. On the other hand, matter is needed to
mediate interactions between photons and thus to implement nonlinear optics.
The recent advent of experimental platforms realising a non-relativistic version of Quantum
Electrodynamics (QED) by confining light around quantum materials1–3 — with an effective fine structure
constant being of order 1 — allows to explore material’s control and nonlinear optics in a novel regime where
both light and matter have a finite density and strong quantum correlations. The latter can be now also
manipulated using state-of-the-art techniques of quantum optics and material science.
Our research in this field deals with layered materials in solid state as well as ultracold atomic gases, and
follows two main complementary aims (see Figure):
1) To control collective phenomena in materials by preparing the quantum state of the force-carrier
photon using state-of-the-art quantum optics techniques
2) To control quantum nonlinear optics by preparing the many-body state of the quantum degenerate
matter which mediates photon-photon interactions
In this talk, I will discuss two examples showcasing the promise of each of the above aims, and illustrate the
theoretical tools we developed to describe the underlying novel scenarios in few- and many-body physics.

1. Mivehvar, F., Piazza, F., Donner, T. & Ritsch, H. Cavity QED with quantum gases: new paradigms in many-body physics. Adv.
Phys. 70, 1–153 (2021).
2. Garcia-Vidal Francisco J., Ciuti Cristiano, & Ebbesen Thomas W. Manipulating matter by strong coupling to vacuum fields. Science
373, eabd0336 (2021).
3. Schlawin, F., Kennes, D. M. & Sentef, M. A. Cavity Quantum Materials. ArXiv211215018 Cond-Mat Physicsquant-Ph (2021).

If you’d like to participate in the seminar, please contact us!