Room-temperature valley-selective emission in Si-MoSe<sub>2</sub> heterostructures enabled by high-quality-factor chiroptical cavities.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41318601.
- Also identified by DOI 10.1038/s41467-025-66502-4 and PMC identifier 12764782.
- Licence recorded as CC BY-NC-ND.
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Abstract
Transition metal dichalcogenides possess valley pseudospin, enabling coupling between photon spin and electron spin for classical and quantum information processing. However, rapid valley-dephasing processes have impeded the development of scalable, high-performance valleytronic devices operating at room temperature. Here we demonstrate that a chiral resonant metasurface can enable room-temperature valley-selective emission in MoSe<sub>2</sub> monolayers independent of excitation polarization. This platform provides circular eigen-polarization states with a high quality factor (Q-factor) and strong chiral near-field enhancement. The fabricated Si chiral metasurfaces exhibit chiroptical resonances with Q-factors up to 450 at visible wavelengths. We reveal degrees of circular polarization (DOP) reaching a record high of 0.5 at room temperature. Our measurements show that the high DOP can be attributed to the significantly increased chiroptical local density of states, which enhances valley-specific radiative transition rates by a factor of ~13. Our work could facilitate the development of ultracompact chiral classical and quantum light sources.