Twist-tailoring Coulomb correlations in van der Waals homobilayers
Artikel i vetenskaplig tidskrift, 2020
The recent discovery of artificial phase transitions induced by stacking monolayer materials at magic twist angles represents a paradigm shift for solid state physics. Twist-induced changes of the single-particle band structure have been studied extensively, yet a precise understanding of the underlying Coulomb correlations has remained challenging. Here we reveal in experiment and theory, how the twist angle alone affects the Coulomb-induced internal structure and mutual interactions of excitons. In homobilayers of WSe2, we trace the internal 1s–2p resonance of excitons with phase-locked mid-infrared pulses as a function of the twist angle. Remarkably, the exciton binding energy is renormalized by up to a factor of two, their lifetime exhibits an enhancement by more than an order of magnitude, and the exciton-exciton interaction is widely tunable. Our work opens the possibility of tailoring quasiparticles in search of unexplored phases of matter in a broad range of van der Waals heterostructures.
Författare
Philipp Merkl
Universität Regensburg
F. Mooshammer
Universität Regensburg
Samuel Brem
Chalmers, Fysik, Kondenserad materie- och materialteori
Anna Girnghuber
Universität Regensburg
Kai Qiang Lin
Universität Regensburg
Leonard Weigl
Universität Regensburg
Marlene Liebich
Universität Regensburg
Chaw Keong Yong
Universität Regensburg
Roland Gillen
Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)
Janina Maultzsch
Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)
J. M. Lupton
Universität Regensburg
Ermin Malic
2D-Tech
Chalmers, Fysik, Kondenserad materie- och materialteori
R. Huber
Universität Regensburg
Nature Communications
2041-1723 (ISSN) 20411723 (eISSN)
Vol. 11 1 2167Excitondynamik i atomiskt tunna material
Vetenskapsrådet (VR) (2018-00734), 2019-01-01 -- 2024-12-31.
Graphene Core Project 3 (Graphene Flagship)
Europeiska kommissionen (EU) (EC/H2020/881603), 2020-04-01 -- 2023-03-31.
Ämneskategorier
Fysikalisk kemi
Atom- och molekylfysik och optik
Den kondenserade materiens fysik
DOI
10.1038/s41467-020-16069-z