Spatial extent of the excited exciton states in WS$_2$ monolayers from diamagnetic shifts
| Autor: | Zipfel, Jonas, Holler, Johannes, Mitioglu, Anatolie A., Ballottin, Mariana V., Nagler, Philipp, Stier, Andreas V., Taniguchi, Takashi, Watanabe, Kenji, Crooker, Scott A., Christianen, Peter C. M., Korn, Tobias, Chernikov, Alexey |
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| Rok vydání: | 2018 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.98.075438 |
| Popis: | We experimentally study the radii of excitons in hBN-encapsulated WS2 monolayers by means of magneto-optical reflectance spectroscopy at cryogenic temperatures in magnetic fields up to 29 T. We observe field-induced energy shifts of the exciton ground and excited states due to valley Zeeman and diamagnetic effects. We find the g factor of the first excited state of $-4.2(+/-0.1) to be essentially equal to that of the ground state of -4.35(+/-0.1). From diamagnetic shifts we determine the root mean square radii of the excitons. The radius of the first excited state is found to be 5-8 nm and that of the ground state around 2 nm. Our results further confirm the Wannier-Mott nature of the exciton quasiparticles in monolayer semiconductors and the assignment of the optical resonances in absorption-type measurements. They also provide additional support for the applicability of the effective mass hydrogenlike models in these systems. Comment: accepted for publication in Phys. Rev. B |
| Databáze: | arXiv |
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