Photon-mediated effective electron-electron interactions (EEIs) have been known for a long time [1] to yield one of the harshest forms of non-Fermi-liquid states of matter which have been revealed so far. These EEIs have been recently revisited in the context of cavity-QED of strongly correlated electron systems. In particular, it has been predicted [2] that two-dimensional electron gases placed inside Terahertz cavities display an exotic form of superconductivity, known in the field of high-Tc superconductors as “Amperean” superconductivity [3].
I will discuss some recent unpublished results [4] on the possibility to engineer Amperean superconductivity in a graphene sheet embedded in an optical cavity, highlighting in particular subtleties associated with the difference between longitudinal and transverse electromagnetic fluctuations.
[1] M. Yu. Reizer, Phys. Rev. B 39, 1602 (1989).
[2] F. Schlawin, A. Cavalleri, and D. Jaksch, Phys. Rev. Lett. 122, 133602 (2019).
[3] See e.g. P. A. Lee, Phys. Rev. X 4, 031017 (2014) and references therein.
[4] A. De Pasquale, G. M. Andolina, F. M. D. Pellegrino, I. Torre, F. H. L. Koppens, and M. Polini, to be published.
