Cavity-mediated electron interactions and photo-induced electron pairing

by Dr Frank Schlawin (Hamburg University and Max Planck Institute for the Structure and Dynamics of Matter)

Tuesday 19 Oct 2021, 16:00 → 17:00 Asia/Shanghai

TDLI Meeting Room 200

Abstract

Recent years have witnessed the development of a new generation of nanoplasmonic cavities, which can reach the ultrastrong coupling regime with dipolar materials. First experiments demonstrate cavity-induced changes to quasiparticle mobility and lifetimes [1] or even the enhancement of the critical temperatures in a molecular superconductor by an astonishing 50% [2]. This has created considerable interest in the possibilities of manipulating electronic ground states and shaping collective excitations in two-dimensional materials with the strong coupling to electromagnetic cavities.

 

In my talk, I will briefly introduce current ideas and challenges in this emerging field. Then I will discuss our proposal of enhancing electronic interactions in cavities [3], where I will argue that the strong confinement of the electromagnetic field in nanoplasmonic cavities could increase such interaction effects to experimentally accessible temperatures. I will then present how laser driving an electron-cavity system can induce and control the sign of electron interactions [4]. Their peculiar long-range character can give rise to new collective modes and stabilize Higgs mode oscillations in superconductors [5].

[1] G. L. Paravicini-Bagliani et al., Nature Phys. 15, 186 (2019)
[2] A. Thomas et al., arXiv: 1911.01459
[3] F. Schlawin, A. Cavalleri and D. Jaksch, Phys. Rev. Lett. 122, 133602 (2019)
[4] H. Gao, F. Schlawin, A. Cavalleri, M. Buzzi, and D. Jaksch, Phys. Rev. Lett. 125, 053602 (2020)
[5] H. Gao, F. Schlawin, and D. Jaksch, arXiv: 2106.05076 (accepted as Phys. Rev. B (Lett.), 2021)

Biography

I completed my PhD at the University of California, Irvine, USA, under the supervision of Prof. Shaul Mukamel, and at the University of Freiburg, Germany, from which I received my degree, under the supervision of Prof. Andreas Buchleitner. In 2015, I joined the group of Prof. Dieter Jaksch at the University of Oxford, where I worked in the ERC Synergy Grant “Q-MAC” (Frontiers in Quantum Materials’ Control). In 2020, I then moved to Hamburg to work as a group leader at the Centre for Ultrafast Imaging (CUI) and the Max Planck Institute for the Structure and Dynamics of Matter.

My research interests span modern research areas concerning the interaction of quantum light with complex quantum systems. Since the time of my PhD, I work on the theory of nonlinear spectroscopy with quantum light. My research particularly focusses on the role of photonic quantum correlations in absorption processes, and how these can be employed for spectroscopic applications. Besides, I am most interested in the prospect of using optical cavities to manipulate material properties in the strong coupling regime. Here, my main interest lies in the control of many-body correlations in complex solids.

Division

Condensed Matter

Other information

Zoom Link: https://cern.zoom.us/j/68313549553?pwd=QWttRnZhY2F1Qm1WV1phMmhCMDFOZz09
Meeting ID: 683 1354 9553                 Password: 123456