Lasing of moiré trapped MoSe<sub>2</sub>/WSe<sub>2</sub> interlayer excitons coupled to a nanocavity.

Qian, Chenjiang; Troue, Mirco; Figueiredo, Johannes; Soubelet, Pedro; Villafañe, Viviana; Beierlein, Johannes; Klembt, Sebastian; Stier, Andreas V et al. · Sci Adv · 2024

basic_science · Level V

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Abstract

We report lasing of moiré trapped interlayer excitons (IXs) by integrating a pristine hBN-encapsulated MoSe<sub>2</sub>/WSe<sub>2</sub> heterobilayer into a high-<i>Q</i> (>10<sup>4</sup>) nanophotonic cavity. We control the cavity-IX detuning using a magnetic field and measure their dipolar coupling strength to be 78 ± 4 micro-electron volts, fully consistent with the 82 micro-electron volts predicted by theory. The emission from the cavity mode shows clear threshold-like behavior as the transition is tuned into resonance with the cavity. 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 pronounced at resonance while weak off-resonance. Our results show that a lasing transition can be induced in interacting moiré IXs with macroscopic coherence extending over the length scale of the cavity mode. Such systems raise interesting perspectives for low-power switching and synaptic nanophotonic devices using two-dimensional materials.