Interlayer excitons at the tunable Moire line defect
Abstract
Van der Waals stacking of two monolayers semiconducting transition metal dichalcogenides is a powerful approach to create semiconductor heterojunctions for engineering functional devices. The inevitable mismatch in lattice constants and crystallographic axes leads to the formation of Moire pattern, giving new possiblilities to tailor the material properties. Interlayer excitons in such moire pattern experience an effective superlattice potential and have a nanoscale patterned light-coupling properies. The low energy physics of those excitons can be described by a tight binding model with giant spin-orbit coupling. Here, we investigate interlayer excitons in such moire pattern with a line defect due to the twin domain boudary in one of the layers, which can localize one-dimensional excitonic modes of topological origin. We show that the defect configuration in the Moire superlattice can be tuned by the interlayer translation, twisting angle and reflects the atomic configuration of the domain boundary. The effects of the Moire line defect configuration on the exciton modes are systematically investigated. We also find the defect exciton mode has distinct light-coupling properties on the two sides of the twin domain boundary.
Research Grant Council of HKSAR (HKU17302617, C7036-17).- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MART70311T