Cavity-mediated effects in disordered quantum Hall systems
Cristiano Ciuti (laboratoire Matériaux et Phénomènes Quantiques)
Onsite seminar + zoom (ID: 961 6880 9559, PW: h2LNDE).
The manipulation of matter by giant vacuum fields in electromagnetic resonators is an emergent topic in physics and chemistry [1]. In this seminar, we will see how the cavity vacuum fluctuations affect the physics of disordered quantum Hall systems [2]. In particular, we will show how, in the presence of electronic disorder, the cavity can mediate long-range electron hopping via the exchange of a virtual photon, involving both edge and bulk states. Such an effect produces a breakdown of the topological protection of the integer quantum Hall effect as demonstrated in recent transport experiments [3].
[1] F. J. Garcia-Vidal, C. Ciuti, T. W. Ebbesen, Manipulating matter by strong coupling to vacuum fields, Science 373,178 (2021).
[2] C. Ciuti, Cavity-mediated electron hopping in disordered quantum Hall systems, Phys. Rev. B 104, 155307 (2021).
[3] F. Appugliese, J. Enkner, G. L. Paravicini-Bagliani, M. Beck, C. Reichl, W. Wegscheider, G. Scalari, C. Ciuti, J. Faist, Breakdown of the topological protection by cavity vacuum fields in the integer quantum Hall effect, preprint arXiv:2107.14145 (2021)