Polaritonic Chern insulators in monolayer semiconductors

Abstract

Systems with strong light-matter interaction opens up new avenues for studying topological phases of matter. Examples include exciton-polaritons, mixed light-matter quasiparticles, where the topology of the polaritonic band structure arises from the collective coupling between matter wave and optical fields strongly confined in periodic dielectric structures. Distinct from light-matter interaction in a uniform environment, the spatially varying nature of the optical fields leads to a fundamental modification of the well-known optical selection rules, which were derived under the plane wave approximation. Here we identify polaritonic Chern insulators by coupling valley excitons in transition metal dichalcogenides (TMDs) to photonic Bloch modes in a dielectric photonic crystal (PhC) slab. We show that polaritonic Dirac points (DPs), which are markers for topological phase transition points, can be constructed from the collective coupling between valley excitons and photonic Dirac cones in the presence of both time-reversal and inversion symmetries. Lifting exciton valley degeneracy by breaking time-reversal symmetry leads to gapped polaritonic bands with non-zero Chern numbers. Through numerical simulations, we predict polaritonic chiral edge states residing inside the topological gaps. Our work paves the way to further explore polaritonic topological phases and their practical applications in polaritonic devices.

References in corpus (14)

• Topological Photonics
• Chiral Quantum Optics
• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Observation of Superfluidity of Polaritons in Semiconductor Microcavities
• Magnetic Control of Valley Pseudospin in Monolayer WSe2
• Valley Zeeman Effect in Elementary Optical Excitations of a Monolayer WSe2
• Exciton-polariton condensates
• Bulk Topological Invariants in Noninteracting Point Group Symmetric Insulators
• Ultrafast Generation of Pseudo-magnetic Field for Valley Excitons in WSe2 Monolayers
• Topological Polaritons
• Polariton $\mathbb{Z}$ Topological Insulator
• Van der Waals Heterostructure Polaritons with moiré-Induced Nonlinearity
• Topological Polaritons and Excitons in Garden Variety Systems
• Giant effective Zeeman splitting in a monolayer semiconductor realized by spin-selective strong light-matter coupling

Cited by in corpus (5)

• 2D material exciton-polariton transport on 2D photonic crystals
• Tunable Nanophotonic Devices and Cavities based on a Two-Dimensional Magnet
• Polariton Chern Bands in 2D Photonic Crystals Beyond Dirac Cones
• Anisotropic exciton-polaritons reveal non-Hermitian topology in van der Waals materials
• Engineering strong coupling in ultra-compact photonic crystal/2D material platforms