[7p-N203-1~14] 4.1 Plasmonics and Nanophotonics

3:30 PM - 3:45 PM JST(6:30 AM - 6:45 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[7p-N203-7] Landau Polaritons in Nanoslots in the Ultrastrong Coupling Regime: Breakdown of the Electric-Dipole Approximation

〇(B)Sae Endo¹, Dasom Kim¹, Sunghwan Kim², Dukhyung Lee³, Shuang Liang⁴, Geon Lee^5,6, Michael J. Manfra⁴, Minah Seo^5,7, Dai-Sik Kim^2,6, Junichiro Kono¹ (1.Rice Univ., 2.Ulsan National Inst. of Sci. and Tech., 3.Mohammed VI Polytechnic Univ., 4.Purdue Univ., 5.Korea Inst. of Sci. and Tech., 6.Seoul National Univ., 7.Korea Univ.)

Keywords:

Landau polaritons,Nanoslot cavities,Ultrastrong coupling

Landau polaritons arise when cavity photons strongly couple, or hybridize, with the cyclotron resonance of two-dimensional electrons in a strong perpendicular magnetic field. Theories of Landau polaritons are well-developed under the electric-dipole approximation, including the selection rules for inter-Landau-level transitions. Recently, some anomalies have been observed for Landau polaritons in small-mode-volume plasmonic cavities, which were interpreted as a result of nonlocal coupling of cavity photons with finite-momentum magnetoplasmons. However, the degree of spatial confinement was limited by fabrication constraints to fully investigate the breakdown of the electric-dipole approximation. Here, we explore the behavior of Landau polaritons beyond the electric-dipole approximation by confining light in nanoslots whose widths are smaller than the cyclotron radius. We observed a normally forbidden cyclotron transition with frequency ω = 2ω_c.