Interfacial anisotropic exciton-polariton manifolds in ReS$_2$

TL;DR

This paper demonstrates the creation and control of highly anisotropic exciton-polaritons in ReS$_2$, enabling tunable light-matter interactions for advanced polariton-based devices.

Contribution

It introduces a novel method to generate and manipulate anisotropic exciton-polaritons in biaxial layered semiconductors with tunable coupling regimes.

Findings

Achieved Rabi splitting up to 68 meV.

Controlled transition from weak to strong coupling via polarization rotation.

Tunable light-matter coupling by varying layer number.

Abstract

Light-matter coupling in van der Waal's materials holds significant promise in realizing Bosonic condensation and superfluidity. The underlying semiconductor's crystal asymmetry, if any, can be utilized to form anisotropic half-light half-matter quasiparticles. We demonstrate generation of such highly anisotropic exciton-polaritons at the interface of a biaxial layered semiconductor, stacked on top of a distributed Bragg reflector. The spatially confined photonic mode in this geometry couples with polarized excitons and their Rydberg states, creating a system of highly anisotropic polariton manifolds, displaying Rabi splitting of up to 68 meV. Rotation of the incident beam polarization is used to tune coupling strength and smoothly switch regimes from weak to strong coupling, while also enabling transition from one three-body coupled oscillator system to another. Light-matter coupling is further tunable by varying the number of weakly coupled optically active layers. Our work provides a versatile method of engineering devices for applications in polarization-controlled polaritonics and optoelectronics.