Shi, Q, Shih, E-M, Rhodes, D et al. (8 more authors) (2022) Bilayer WSe2 as a natural platform for interlayer exciton condensates in the strong coupling limit. Nature Nanotechnology, 17 (6). pp. 577-582. ISSN 1748-3387
Abstract
Exciton condensates (ECs) are macroscopic coherent states arising from condensation of electron–hole pairs1. Bilayer heterostructures, consisting of two-dimensional electron and hole layers separated by a tunnel barrier, provide a versatile platform to realize and study ECs2,3,4. The tunnel barrier suppresses recombination, yielding long-lived excitons5,6,7,8,9,10. However, this separation also reduces interlayer Coulomb interactions, limiting the exciton binding strength. Here, we report the observation of ECs in naturally occurring 2H-stacked bilayer WSe2. In this system, the intrinsic spin–valley structure suppresses interlayer tunnelling even when the separation is reduced to the atomic limit, providing access to a previously unattainable regime of strong interlayer coupling. Using capacitance spectroscopy, we investigate magneto-ECs, formed when partially filled Landau levels couple between the layers. We find that the strong-coupling ECs show dramatically different behaviour compared with previous reports, including an unanticipated variation of EC robustness with the orbital number, and find evidence for a transition between two types of low-energy charged excitations. Our results provide a demonstration of tuning EC properties by varying the constituent single-particle wavefunctions.
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Copyright, Publisher and Additional Information: | © The Author(s), under exclusive licence to Springer Nature Limited 2022. This is an author produced version of an article, published in Nature Nanotechnology. Uploaded in accordance with the publisher's self-archiving policy. | ||||
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Institution: | The University of Leeds | ||||
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Theoretical Physics (Leeds) | ||||
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Depositing User: | Symplectic Publications | ||||
Date Deposited: | 12 Jul 2022 15:13 | ||||
Last Modified: | 18 Oct 2022 00:32 | ||||
Status: | Published | ||||
Publisher: | Nature Research | ||||
Identification Number: | https://doi.org/10.1038/s41565-022-01104-5 | ||||
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