Lasing of moiré trapped MoSe2/WSe2 interlayer excitons coupled to a nanocavity
Abstract
Moiré trapped interlayer excitons (IXs) in heterobilayer transition metal dichalcogenides currently attract strong interest due to their potential for non-classical light generation, coherent spin-photon interfaces and exploring novel correlated phases of electrons. Here, we report lasing of moiré trapped IXs by integrating a pristine hBN-encapsulated MoSe2/WSe2 heterobilayer in a high-Q (> 104) nanophotonic cavity. We control the detuning between the IX line and the cavity mode with a magnetic field and measure the dipolar coupling strength to the cavity mode to be 78 ± 4 μeV, fully consistent with the 82 μeV predicted by theory. The emission from the cavity mode shows clear threshold-like behavior. We observe a superlinear power dependence accompanied by a narrowing of the linewidth as the distinct features of lasing. The onset and prominence of these threshold-like behaviors are significant at resonance whilst weak off-resonance. Our results show that a lasing transition can be induced in interacting moiré trapped IXs with macroscopic coherence extending over the lengthscale of the cavity mode. Such systems raise interesting perspectives for low-power switching and synaptic nanophotonic devices using 2D materials.
README: · Lasing of Moiré Trapped MoSe2/WSe2 Interlayer Excitons Coupled to a Nanocavity
https://doi.org/10.5061/dryad.f1vhhmh38
These datasets were collected using the confocal micro-photoluminescence (PL) setup for the spectroscopy of cavity-moiré interlayer exciton (IX) coupling. We controlled the excitation power and exciton-photon detuning to demonstrate the coupling and lasing in the system. We further investigated the system with the excitation laser at different wavelength to manipulatie the exciton photo-physics and the non-linearity in lasing.
Description of the data and file structure
Coupling.opju is the data for exciton-photon coupling at low excitation power.
- In folder 1c, "PLs-noise corrected" is the figure and corresponding data for the magneto PL spectra. "PLs-raw" is the raw data before noise datapoints are corrected.
- In folder 1b, "step1 PLs-baseline subtracted" is the data in which the emission baseline is subtracted. "step2 fit g" is the cavity peak linewidth extracted by fitting the data in "step1 PLs-baseline subtracted". The second fitting of the cavity peak linewidth in "step2 fit g" shows the exciton-photon coupling strength g.
Lasing.opju is the power- and detuning- dependent data to demonstrate the lasing.
- Four folders "0.5T", "1.8T", "4T", "7T" correspond to the power-dependent spectra recorded at different magnetic fields. The different magnetic fields correspond to different exciton-photon detuning. In each folder, "PLs-raw" is the raw data, "PLs-baseline subtracted" is the data in which the emission baseline is subtracted, and "fit" is the power-dependent cavity peak intensity and linewidth extracted by fitting the data in "PLs-baseline subtracted". The lasing phenomena, i.e., non-linearity and linewidth narrowing, is significant near the exciton-photon resonance (0.5T and 1.8T) whilst weak off-resonance (4T and 7T), demonstrating the lasing arising from exciton-photon coupling.
Lasing_532nm.opju is the control experiment under the green laser excitation.
- Two folders "Mode1" and "Mode2" correspond to the power-dependent spectra recorded from two different cavity modes. In each folder, "PLs-raw" is the raw data, "PLs-baseline subtracted" is the data in which the emission baseline is subtracted, and "fit" is the power-dependent cavity peak intensity and linewidth extracted by fitting the data in "PLs-baseline subtracted". Under the green laser excitation, the lasing phenomena, i.e., non-linearity and linewidth narrowing, is significant compared to the red laser excitation in "Lasing.opju".