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Polaritonic Chern Insulators in Monolayer Semiconductors
Li He1, Jingda Wu2, Jicheng Jin1
1Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Physical Review Letters
|February 10, 2023
Summary
Researchers created polaritonic Chern insulators by coupling excitons in transition metal dichalcogenides with photonic crystals. This work enables the study of topological phases in nanophotonic structures and polaritonic devices.
Area of Science:
- Condensed Matter Physics
- Quantum Optics
- Materials Science
Background:
- Strong light-matter interaction is key to exploring topological phases.
- Exciton polaritons, formed by coupling excitons and photons, exhibit unique topological properties.
- Standard optical selection rules are modified in confined photonic structures.
Purpose of the Study:
- To identify and characterize polaritonic Chern insulators.
- To explore the formation of polaritonic Dirac points for topological phase transitions.
- To investigate the potential for chiral edge states in these systems.
Main Methods:
- Coupling valley excitons in transition metal dichalcogenides to photonic Bloch modes.
- Utilizing dielectric photonic crystal slabs for strong light confinement.
- Employing numerical simulations to predict band structures and edge states.
Main Results:
- Polaritonic Chern insulators were identified by coupling excitons to photonic crystal modes.
- Polaritonic Dirac points were constructed by combining valley excitons and photonic Dirac cones.
- Breaking time-reversal symmetry opened topological gaps with nonzero Chern numbers, revealing chiral edge states.
Conclusions:
- This study demonstrates a pathway to realizing topological phases in nanophotonic systems.
- The findings open new avenues for strong exciton-photon interaction research.
- The work has implications for the development of novel polaritonic topological devices.
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