Parts | Days | Selection | Search | Updates | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 8: 2D Materials II (joint session HL/CPP)
HL 8.1: Talk
Monday, March 27, 2023, 15:00–15:15, POT 81
Twist- and gate-tunable valley splitting in TMDC/CrI3 heterostructures — •Klaus Zollner, Paulo E. Faria Junior, and Jaroslav Fabian — Institute of Theoretical Physics, University of Regensburg, 93053 Regensburg, Germany
Van der Waals heterostructures composed of twisted monolayers promise great tunability of electronic, optical, and magnetic properties. Twistronics has already demonstrated its potential in tuning proximity spin-orbit and exchange coupling in graphene-based heterostructures [1,2]. In this talk, we present the strong manipulation of the valley splitting upon twisting and gating in TMDC/CrI3 heterostructures [3]. In particular, upon twisting from 0∘ to 30∘, the proximity-induced TMDC valence band edge exchange splitting can be reversed (−2 to 2 meV), while the TMDC conduction band edge exchange splitting remains nearly constant (−3 meV). Further giant tunability (few meV) of the proximity exchange coupling is provided by a transverse electric field. Consequently, twisting and gating then allow to tailor the valley splitting of the first intralayer exciton peak in the range of 0 to 12 meV in WSe2/CrI3, which is equivalent to gigantic external magnetic fields of up to about 60 Tesla.
This work was supported by DFG SFB 1277, DFG SPP 2244, and the EU Horizon 2020 Research and Innovation Program (Graphene Flagship).
[1] K. Zollner and J. Fabian, Phys. Rev. Lett. 128, 106401 (2022).
[2] Lee et al., Phys. Rev. B 106, 165420 (2022).
[3] K. Zollner, P. E. F. Junior, J. Fabian, arXiv:2210.13794 (2022).