Room-temperature Tamm-plasmon exciton-polaritons with a WSe2 monolayer

Abstract

Solid-state cavity quantum electrodynamics is a rapidly advancing field, which explores the frontiers of light–matter coupling. Metal-based approaches are of particular interest in this field, as they carry the potential to squeeze optical modes to spaces significantly below the diffraction limit. Transition metal dichalcogenides are ideally suited as the active material in cavity quantum electrodynamics, as they interact strongly with light at the ultimate monolayer limit. Here, we implement a Tamm-plasmon-polariton structure and study the coupling to a monolayer of WSe2, hosting highly stable excitons. Exciton-polariton formation at room temperature is manifested in the characteristic energy–momentum dispersion relation studied in photoluminescence, featuring an anti-crossing between the exciton and photon modes with a Rabi-splitting of 23.5 meV. Creating polaritonic quasiparticles in monolithic, compact architectures with atomic monolayers under ambient conditions is a crucial step towards the exploration of nonlinearities, macroscopic coherence and advanced spinor physics with novel, low-mass bosons.

Excitonic effects in the optical properties of 2D materials:an equation of motion approach

“…For the particular case of two band systems, as in the case given by the Hamiltonian (6), we split equation (A.8) into various terms. For λ = λ we have: 9) and for λ = −λ we find: …”

“…This has attracted a wealth of scientific research [7,8,9,10,11,12,13,14,15,16,17,18,19,20,22,23]. The signature of excitons appeared first in the optical measurements of monolayer MoS 2 [5], where two peaks in the absorbance, with energies ∼ 1.9 eV and ∼ 2.1 eV, were identified.…”

Control of Coherently Coupled Exciton Polaritons in Monolayer Tungsten Disulphide

“…More importantly, to maintain unperturbed coherent coupling at high pump density, support strong nonlinear polariton interactions and slow down the polariton leakage rate with respect to the nonlinear interaction rate, a large SLR is essential for polariton condensation [24]. After the first demonstration of exciton-polaritons in a MoS 2 monolayer-based MC [12], various approaches [13][14][15][16][17][18] have been employed for further polariton study, but with limitations on reduced Rabi splitting, low temperature operation (< 20 K), and small SLR (typically < 2). These limitations prevent coherent strong coupling at high pump injection, which is the key for room temperature polariton condensation.…”

One-dimensional Tamm plasmons: Spatial confinement, propagation, and polarization properties

“…Most of them are based on a TP coupling with other excitations, including a SP [5][6][7], Bragg cavity mode [8,9], exciton confined either in a quantum well [10] embedded inside the BM or in a monolayer of the transition-metal dichalcogenide [11,12], and also point emitters like quantum dots [13], organic molecules [14], etc. The strong field enhancement in the vicinity of a surface allows for attaining the strong-coupling regime [10,11], while a comparatively small mode volume of TPs localized beneath the small metal disk allows using the resonant TP structures to control the spontaneous emission of a semiconductor quantum dot through the Purcell effect [13]. The latter phenomenon can also be used for creation of single-photon sources [15].…”