Sub-meV Linewidth Nanocavity Trion-Polaritons in a Semiconductor Monolayer

Oral-In-person

Abstract

Trion-polaritons in transition metal dichalcogenide (TMD) monolayers—hybrid quasiparticles formed by the strong coupling between trion resonances and optical cavity modes—offer a powerful platform for exploring many-body physics and realizing novel photonic devices such as polariton transistors and lasers. However, their linewidths are often limited by material quality, inhomogeneity, and cavity losses.

In this work, we demonstrate ultranarrow-linewidth trion-polaritons by strongly coupling a high-Q indium gallium phosphide (InGaP) nanobeam photonic crystal cavity mode to the trion resonance in a monolayer MoSe₂. The cavity is engineered to achieve a quality factor exceeding 5000 at the trion resonance. We observe a Rabi splitting of approximately 30 meV, and, notably, the lower polariton branch exhibits an exceptionally narrow linewidth of 0.8 meV—significantly smaller than previously reported values for TMD polaritons.

These results establish a new platform for investigating coherent and nonlinear quantum phenomena in two-dimensional polariton systems. We are currently exploring the system’s nonlinear optical response, with preliminary measurements indicating strong optical nonlinearities.

Presenters

  • Zhi Wang

    • University of Pennsylvania

Authors

  • Zhi Wang

    • University of Pennsylvania
  • Li He

    • University of Pennsylvania
  • Xiang Lu

    • University of Pennsylvania
  • Zhengyi Yang

  • Yiming Pang

  • Galan Moody

    • University of California, Santa Barbara
  • Bo Zhen

    • University of Pennsylvania