Highly Polarized Single Photons from Strain-Induced Quasi-1D Localized Excitons in WSe<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34424710.
- Also identified by DOI 10.1021/acs.nanolett.1c01927 and PMC identifier 8431731.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Single photon emission from localized excitons in two-dimensional (2D) materials has been extensively investigated because of its relevance for quantum information applications. Prerequisites are the availability of photons with high purity polarization and controllable polarization orientation that can be integrated with optical cavities. Here, deformation strain along edges of prepatterned square-shaped substrate protrusions is exploited to induce quasi-one-dimensional (1D) localized excitons in WSe<sub>2</sub> monolayers as an elegant way to get photons that fulfill these requirements. At zero magnetic field, the emission is linearly polarized with 95% purity because exciton states are valley hybridized with equal shares of both valleys and predominant emission from excitons with a dipole moment along the elongated direction. In a strong field, one valley is favored and the linear polarization is converted to high-purity circular polarization. This deterministic control over polarization purity and orientation is a valuable asset in the context of integrated quantum photonics.