Twist-tailoring Coulomb correlations in van der Waals homobilayers
| Autor: | Rupert Huber, Janina Maultzsch, Marlene Liebich, Kai-Qiang Lin, Fabian Mooshammer, Leonard Weigl, John M. Lupton, Ermin Malic, Anna Girnghuber, Chaw-Keong Yong, Samuel Brem, Roland Gillen, Philipp Merkl |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Phase transition
Nonlinear optics Solid-state physics Science Exciton Atom and Molecular Physics and Optics General Physics and Astronomy 02 engineering and technology Two-dimensional materials 01 natural sciences Resonance (particle physics) Physical Chemistry General Biochemistry Genetics and Molecular Biology Article symbols.namesake Condensed Matter::Materials Science Ultrafast photonics 0103 physical sciences Coulomb lcsh:Science 010306 general physics Electronic band structure Physics Multidisciplinary Condensed matter physics ddc:530 General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 530 Physik 3. Good health symbols Quasiparticle lcsh:Q van der Waals force 0210 nano-technology |
| Zdroj: | Nature Communications Nature Communications (2041-1723) vol.11(2020) Nature Communications, Vol 11, Iss 1, Pp 1-7 (2020) |
| Popis: | 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. The crystallographic orientation of monolayers in van der Waals multi-layers controls their electronic and optical properties. Here the authors show how the twist angle affects Coulomb correlations governing the internal structure and the mutual interaction of excitons in homobilayers of WSe2. |
| Databáze: | OpenAIRE |
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