Diffusivity Reveals Three Distinct Phases of Interlayer Excitons in MoSe2/WSe2 Heterobilayers
| Autor: | Lin Zhou, Yusong Bai, Cory Dean, Jue Wang, En-Min Shih, Xiaolin Zhu, Qianhui Shi, Wenjing Wu, Katayun Barmak, Daniel Rhodes, James Hone |
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| Rok vydání: | 2021 |
| Předmět: |
Condensed Matter::Quantum Gases
Physics Phase transition Photoluminescence Condensed matter physics Condensed Matter::Other Exciton Photoconductivity General Physics and Astronomy Charge (physics) Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 01 natural sciences Mott transition Condensed Matter::Materials Science Dipole 0103 physical sciences Coulomb 010306 general physics |
| Zdroj: | Physical Review Letters. 126 |
| ISSN: | 1079-7114 0031-9007 |
| DOI: | 10.1103/physrevlett.126.106804 |
| Popis: | Charge separated interlayer excitons in transition metal dichalcogenide heterobilayers are being explored for moir\'e exciton lattices and exciton condensates. The presence of permanent dipole moments and the poorly screened Coulomb interaction make many-body interactions particularly strong for interlayer excitons. Here we reveal two distinct phase transitions for interlayer excitons in the ${\mathrm{MoSe}}_{2}/{\mathrm{WSe}}_{2}$ heterobilayer using time and spatially resolved photoluminescence imaging: from trapped excitons in the moir\'e potential to the modestly mobile exciton gas as exciton density increases to ${n}_{ex}\ensuremath{\sim}{10}^{11}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$ and from the exciton gas to the highly mobile charge separated electron-hole plasma for ${n}_{ex}g{10}^{12}\text{ }\text{ }{\mathrm{cm}}^{\ensuremath{-}2}$. The latter is the Mott transition and is confirmed in photoconductivity measurements. These findings set fundamental limits for achieving quantum states of interlayer excitons. |
| Databáze: | OpenAIRE |
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