Electrically reconfigurable dipolar polaritons with highly tunable nonlinearity in a homobilayer microcavity
Baixu Xiang, Yubin Wang, Guihan Wen, Yitong Li, Hao Wen, Zengde She, Haiyun Liu, Kenji Watanabe, Takashi Taniguchi, Timothy C. H. Liew, Zhiyuan Sun, Qihua XiongActive control over optical nonlinearity in solid-state systems is central to unlocking exotic many-body phenomena and photonic devices. While exciton-polaritons in transition metal dichalcogenides (TMDs) offer a promising platform, their practical utility is impeded by fixed interactions and a trade-off between nonlinearity and oscillator strength. Here, we report electrically tunable dipolar polaritons in a dual-gated bilayer MoS 2 microcavity, demonstrating in situ reshaping of the dispersion and modulation of the light-matter coupling strength via the quantum-confined Stark effect. Crucially, this electrical control yields a seven-fold enhancement of the polariton-polariton interaction strength. This enhancement arises from the combined tuning of the effective exciton-exciton interaction and the excitonic Hopfield coefficient. In addition, electrostatic doping provides an independent knob to continuously drive a strong-to-weak coupling crossover. Our findings establish dual-gated TMD homobilayer as a versatile platform for on-chip, dynamically reconfigurable nonlinear light-matter physics.