Regensburg 2022 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

DS: Fachverband Dünne Schichten

DS 17: 2D Materials 6 (joint session DS/CPP)

DS 17.2: Vortrag

Mittwoch, 7. September 2022, 11:30–11:45, H17

Moiré-Bose-Hubbard model for interlayer excitons in twisted transition metal dichalcogenide heterostructures — •Niclas Götting, Frederik Lohof, and Christopher Gies — Institute for Theoretical Physics, University of Bremen, Bremen

Introducing a twist between two superimposed TMD monolayers results in a new superlattice whose properties heavily depend on the twist angle. These so-called moiré structures of TMD materials like MoS₂/WS₂ can host interlayer excitons (IXs) which perceive the varying atomic registry over the moiré unit cell as an effective moiré potential. In such structures, correlated states can emerge, in which the IXs are strongly localized to the potential minima due to exciton-exciton interactions.

We investigate the phases of these trapped moiré IXs by approximating them as bosonic particles and mapping the system onto a Bose-Hubbard model [1]. Our methods allow us to calculate the hopping and two-particle interaction terms of the Bose-Hubbard model for n-th nearest neighbors. To examine the strong impact of dielectrics surrounding the heterobilayer, we introduce a Keldysh potential to the calculation and thereby obtain first results of the twist-angle dependent phases of moiré IXs in twisted TMD heterobilayers.

[1] Götting et al., Phys. Rev. B 105, 165419 (2022)