Abstract

The question of whether sub-wavelength cavities can alter the transport properties of quantum materials is currently attracting a great deal of attention. In this talk I will first present a theoretical framework [1] that allows to quantify the impact of dark sub-wavelength cavities on the properties of quantum materials. I will then show that a paradigmatic magneto-transport phenomenon in two-dimensional (2D) metals, i.e. Shubnikov-de Haas oscillations, is modified by the modes of a sub-wavelength cavity [2]. This effect is intrinsic, totally unrelated to disorder, and stems from the fact that the polariton modes of the cavity alter the Landau parameters of the underlying normal Fermi liquid. As an illustrative example, I will discuss explicit calculations of the Fermi liquid parameters of graphene in a planar van der Waals cavity comprising natural hyperbolic crystals and metal gates. Finally, if time allows, I will show that sub-wavelength cavities can boost the critical temperature of non-phonon superconductors [3].

[1] G. M. Andolina et al., Phys. Rev. B 109 , 104513 (2024).

[2] R. Riolo et al., Proc. Natl. Acad. Sci. (USA) 122, e2407995122 (2025).

[3] R. Riolo et al., to appear on arXiv.