Cavity modification of magnetoplasmon modes through coupling with intersubband polaritons

Year: 2026

Authors: Hale LL., De Bernardis D., Lempereur S., Li LH., Davies AG., Linfield EH., Blaikie T., Deimert C., Wasilewski ZR., Carusotto I., Manceau JM., Jeannin M., Colombelli R., Faist J., Scalari G.

Autors Affiliation: Swiss Fed Inst Technol, Inst Quantum Elect, Auguste Piccard Hof 1, CH-8093 Zurich, Switzerland; Natl Inst Opt CNR INO, LENS Via Nello Carrara 1, I-50019 Sesto Fiorentino, Italy; Univ Leeds, Sch Elect & Elect Engn, Leeds LS2 9JT, England; Univ Waterloo, Dept Elect & Comp Engn, 200 Univ Ave W, Waterloo, ON N2L 3G1, Canada; Univ Trento, Pitaevskii BEC Ctr, CNR INO, I-38123 Trento, Italy; Univ Trento, Dipartimento Fis, I-38123 Trento, Italy; Univ Paris Saclay, Ctr Nanosci & Nanotechnol, CNRS, UMR 9001, F-91120 Palaiseau, France.

Abstract: We investigate the coupling of a multimode metal-insulator-metal cavity to a two-dimensional electron gas (2DEG) in a quantum well in the presence of a strong magnetic field. The TM cavity mode is strongly hybridized with an intersubband transition of the 2DEG, forming a polaritonic mode in the ultrastrong coupling regime, while the TE mode remains an almost purely cavity mode. The magnetoplasmon excitation emerging from the presence of the magnetic field couples with both TM and TE modes, exhibiting different coupling strengths and levels of spatial field inhomogeneity. While the strong homogeneity of the bare TE mode gives rise to the standard anticrossing of strong coupling, the inhomogeneous polaritonic TM mode is shown to activate an observable Coulombic effect in the spectral response, often referred to as nonlocality. This experiment demonstrates a cavityinduced modification of the 2DEG response and offers a route to probing the effect of Coulomb interactions in ultrastrongly coupled systems via reshaping of their cavity mode profiles.

Journal/Review: PHYSICAL REVIEW B

Volume: 113 (12)      Pages from: 125309-1  to: 125309-16

More Information: We thank Gian Marcello Andolina, Bianca Turini, and Alberto Nardin for interesting and insightful discussions. D.D.B. acknowledges funding from the European Union-NextGeneration EU, Integrated infrastructure initiative in Photonic and Quantum Sciences-I-PHOQS [IR0000016, ID No. D2B8D520, CUP B53C22001750006] . I.C. acknowledges support from the Provincia Autonoma di Trento; from the Q@TN Initiative; from the National Quantum Science and Technology Institute through the PNRR MUR Project No. PE0000023-NQSTI, cofunded by the European Union-NextGeneration EU. J.F., G.S., and L.L.H. acknowledge funding through the SNF Grant No. 200021-227521. This work was also supported by the European Union Future and Emerging Technologies (FET) Grant No. 737017 (MIR-BOSE) and partially by the French RENATECH network.
KeyWords: Electron-gas; Oscillations
DOI: 10.1103/6vps-4prq