Observation of hybrid plasmon-photon modes in microwave transmission of coplanar microresonators

Abstract

Microwave transmission of a coplanar microresonator deposited on a sample surface over a two-dimensional electron system has been studied. The transmission signal reveals a series of resonances corresponding to the excitation of hybrid cavity plasmon-photon modes, and ultrastrong plasmon-photon coupling has been realized. The hybridization frequency (Rabi frequency) is shown to be anomalously larger than the frequencies of unperturbed modes and it reaches values of up to 25 GHz. The effect of electron density and magnetic field on the excitation spectrum of cavity polariton has been investigated.

Ultrastrong light-matter coupling at terahertz frequencies with split ring resonators and inter-Landau level transitions

“…In the past few years, a considerable research effort has been devoted to the study of the the ultrastrong light-matter coupling regime. [5][6][7][8][9][10][11][12][13][14][15][16][17] This regime is realized when the vacuum Rabi frequency becomes an appreciable fraction of the unperturbed frequency of the system x. In such a regime, theory predicts modifications of the ground and excited state properties due to the relevance of the counter-rotating terms of the Hamiltonian, resulting in non-adiabatic cavity QED effects.…”

Light-Matter Decoupling in the Deep Strong Coupling Regime: The Breakdown of the Purcell Effect

“…We will consider only normal incidence and, in order to be able to study the coupling in real space, we will take into account all the excited modes of the cavity. The choice of such a system is motivated by the fact that, in its generality, it is a reasonably good toy model for almost all the experiments in which the USC regime has been observed to date [16][17][18][19][20][21], the only exception are superconducting circuits [15], in which a single dipole couples to the cavity field.…”

“…This choice was more than reasonable at a time when the largest observed value was of the order of Ω ω0 ≃ 0.02 [7]. Still, the fascinating new physics observable in the USC regime, ranging from the dynamical Casimir effect [8,9], to superradiant phase transitions [10,11], and ultra-efficient light emission [6,13], stimulated considerable experimental efforts [15][16][17][18][19][20] that have led to the observation of ever increasing values of the normalised coupling in many different systems, with a present world record Ω ω0 = 0.58 [21]. As a consequence, new theoretical investigations, taking a further leap forward, are starting to study what happens when the coupling increases even further and Ω ω0 > 1 [23][24][25][26].…”

Perspectives for gapped bilayer graphene polaritonics

“…The boundary between the two, that is conventionally fixed at ΩR ωx = 0.1, was in fact the coupling value that allowed for the first observation of ultrastrong coupling effects [57]. The ultrastrong coupling regime has been since then observed in a variety of different systems [58][59][60][61][62][63][64][65], with an actual record of ΩR ωx = 0.87 [66]. Excitons in GBG could be very interesting in this regards, a priori allowing to reach or even improve such a record.…”