David Hagenmüller

Institut de Science et d’Ingénierie Supramoléculaires (ISIS), UMR 7006, Université de Strasbourg et CNRS.

Controlling charge and energy transport with cavity quantum electrodynamics

The interplay between light and transport in condensed-matter is at the heart of optoelectronic devices. While it is known that electronic transport in, e.g., quantum Hall systems [1,2], superconductors [3,4], and nanocircuits [5], can be controlled using an external radiation, an interesting question is whether transport properties can be also affected by coupling the relevant matter excitations to the vacuum field of a cavity [6,7]. In particular, one of the most important phenomenon in cavity-quantum electrodynamics is the so-called strong coupling regime, which occurs when the interaction between light and matter is so strong that the latter mix together to create two hybrid light-matter states called “polaritons”, and a continuum of “dark states” that are completely decoupled from light. In this talk, I will discuss different toy models where a chain of two-level systems is resonantly coupled to a cavity field. I will show that the transmission of charges through the chain can be modified by the cavity coupling, leading to a current enhancement even in the dissipative regime where the cavity photon decay rate is the largest parameter [8,9]. The effect of an on-site disorder will be also discussed. Here, we find that the cavity coupling can modify the localization properties of the system and lead to efficient transport of excitations via the dark states [10].

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[2] R. Mani et al. Nature 420, 646 (2002)
[3] A. F. G. Wyatt et al., Phys. Rev. Lett. 16, 1166 (1966)
[4] D. Fausti et al., Science 331, 189 (2011)
[5] M. Ludwig et al., Nat. Phys. 16, 341 (2020)
[6] E. Orgiu et al., Nat. Mater. 14, 1123 (2015)
[7] G. L. Paravicini-Bagliani et al., Nat. Phys. 15, 186 (2019)
[8] D. Hagenmuller et al., Phys. Rev. Lett. 119, 223601 (2017)
[9] D. Hagenmuller et al., Phys. Rev. B 97, 205303 (2018)
[10] T. Botzung et al., Phys. Rev. B 102, 144202 (2020)