Exciton–phonon interactions in nanocavity-integrated monolayer transition metal dichalcogenides

Abstract

Cavity-integrated transition metal dichalcogenide (TMDCs) excitons have recently emerged as a promising platform to study strong light–matter interactions and related cavity quantum electrodynamics phenomena. Although this exciton-cavity system is typically modeled as coupled harmonic oscillators, to account for the rich solid-state environment, the effect of exciton–phonon interaction needs to be incorporated. We model the system by including a phenomenological deformation potential for exciton–phonon interactions and we elucidate the experimentally measured preferential coupling of the excitonic photoluminescence to the cavity modes red-detuned with respect to the exciton resonance. Furthermore, we predict and experimentally confirm the temperature dependence of this preferential coupling. By accurately capturing the exciton–phonon interaction, our model illuminates the potential of cavity-integrated TMDCs for the development of low-power classical and quantum technologies.

Microsphere-coupled light emission control of van der Waals heterostructures

“…The temperature dependence suggests that the asymmetry of the PL emission spectrum is induced by the exciton-phonon coupling similar to that observed in a ring-resonator-coupled WSe2 27 and self-assembled quantum dots in nanocavities 28 . Although the cavity-induced PL reabsorption could also be in effect because of the overlap of the absorption line and the emission energy 29 , we emphasize that our measurement shows the direct evidence of the modulated exciton-phonon coupling through the cavity integration from the observation of the systematic cavity-induced red-shift of the exciton energy as a function of temperature.…”

Dispersive coupling between MoSe2 and a zero-dimensional integrated nanocavity

“…Specifically we observed a dispersive shift in the cavity transmission spectrum as the exciton is temperature-tuned near the cavity resonance. Our efforts extend previous attempts to demonstrate coherent coupling between the TMD exciton and a SiN nanobeam cavity [21] by implementing a clean dry transfer method [22] and recognizing the role of exciton-phonon interactions in the cavity coupled photoluminescence [23]. The extracted excitoncavity coupling from the dispersive shift is hg ≈ 4.3 meV for an estimated cooperativity C = 4g 2 /(κ 0 γ 0 ) ∼ 3.4, in which hγ 0 = 5.77 meV is the measured intrinsic broadening of the TMD exciton, and hκ 0 = 3.8 meV is the bare photonic mode linewidth measured without the TMD material.…”

“…It should be noted the exciton PL peak energy is used as a proxy for the absorption resonance, since MoSe 2 is known to have a small Stokes shift [12]. The extracted light-matter interaction is similar to related nanophotonic structures, although we expect it to be larger with an optimal coverage of the cavity mode [23].…”

Coupling of MoS$_2$ Excitons with Lattice Phonons and Cavity Vibrational Phonons in Hybrid Nanobeam Cavities

“…3(a), where the cavity vibrational phonons provide additional intermediate states (gray replicas) that provide resonance conditions for the scattering of MoS 2 lattice phonons (arrows). Similar vibronic sub-level mediated processes have been reported in photonic [42,43] and plasmonic systems [44,45]. Before further discussion, we first exclude other possibilities.…”