Abstract: Enhancing the light-matter coupling in cavities provides an intriguing route to control properties of matter, from chemical reactions to transport and thermodynamic phase transitions. Order parameters which couple linearly to the electromagnetic field, such as ferroelectricity, incommensurate charge density waves, or exciton condensates, appear most suitable in this context, but the possible mechanisms are not well understood in many cases. In this talk, I will discuss possibilities to manipulate interactions and band structures in a solid via the quantum fluctuations of the electromagnetic field; these results generalize the well-established Floquet engineering of correlated electrons to the regime of quantum light [1]. Specifically, this will be discussed for a model with competing superconductivity and charge density wave order [2]. Moreover, we predict that interactions mediated by the electromagnetic field (more precisely, a surface plasmon mode) can enhance ferroelectric order [3]. Finally, I will discuss possible mechanisms which may explain a recent experiment that shows a cavity-control of the metal-insulator transition in TaS2 [4].
[1] M. A. Sentef, J. Li, F. Künzel, and M. Eckstein, Phys. Rev. Research 2, 033033 (2020).
[2] J. Li and M. Eckstein, Phys. Rev. Lett. 125, 217402 (2020).
[3] K. Lenk, J. Li, Ph. Werner, M. Eckstein, Phys. Rev. B 106, 245124 (2022).
[4] J. Jarc et al., arXiv2210.02346.
JQI Seminars are held on Mondays during Fall and Spring semesters at 11:00 a.m. Eastern Time in Room 2400 of the Atlantic Building. University of Maryland affiliates may participate using Zoom. The seminars are also livestreamed on the JQI YouTube channel (https://www.youtube.com/user/JQInews), which supports audience participation in the chat interface.
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