Theory of magnetotransport for a cavity-embedded two-dimensional electron gas

We present a theory pointing out the crucial role of virtual polariton excitations in controlling the dc charge transport properties of cavity-embedded systems. Specifically, we consider the linear magnetotransport of a cavity-embedded two-dimensional electron gas (2DEG) in the regime where no real photons are injected or created in the resonator [1]. Our theory shows that, for a cavity photon mode with in-plane linear polarization, the dc bulk magnetoresistivity of the 2DEG is anisotropic. For high filling factors of the Landau levels, we predict a profound modification in the envelope of the Shubnikov-de Haas oscillations, with the resistivity being increased or reduced depending on the system parameters (an effect observed in recent experiments [2]). In the limit of low magnetic fields and in the ultrastrong light-matter coupling regime, the resistivity along the cavity-mode polarization direction is enhanced.

[1] N. Bartolo and C. Ciuti, preprint at arXiv:1805.02623, accepted on Phys. Rev. B.
[2] G.L. Paravicini-Bagliani, F. Appugliese, E. Richter, F. Valmorra, J. Keller, M. Beck, N. Bartolo, C. Rössler, T. Ihn, K. Ensslin, C. Ciuti, G. Scalari, and J. Faist, preprint at arXiv:1805.00846, accepted on Nature Physics.