Robust room temperature valley Hall effect of interlayer excitons
The Berry curvature in the band structure of transition metal dichalcogenides (TMDs) introduces a valley-dependent effective magnetic field, which induces the valley Hall effect (VHE). Similar to the ordinary Hall effect, the VHE spatially separates carriers or excitons, depending on their valley in...
| Main Authors: | , , , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2021
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| Online Access: | https://hdl.handle.net/10356/147882 |
| _version_ | 1811695020338577408 |
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| author | Huang, Zumeng Liu, Yuanda Dini, Kévin Tan, Qinghai Liu, Zhuojun Fang, Hanlin Liu, Jin Liew, Timothy Gao, Weibo |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Huang, Zumeng Liu, Yuanda Dini, Kévin Tan, Qinghai Liu, Zhuojun Fang, Hanlin Liu, Jin Liew, Timothy Gao, Weibo |
| author_sort | Huang, Zumeng |
| collection | NTU |
| description | The Berry curvature in the band structure of transition metal dichalcogenides (TMDs) introduces a valley-dependent effective magnetic field, which induces the valley Hall effect (VHE). Similar to the ordinary Hall effect, the VHE spatially separates carriers or excitons, depending on their valley index, and accumulates them at opposite sample edges. The VHE can play a key role in valleytronic devices, but previous observations of the VHE have been limited to cryogenic temperatures. Here, we report a demonstration of the VHE of interlayer excitons in a MoS2/WSe2 heterostructure at room temperature. We monitored the in-plane propagation of interlayer excitons through photoluminescence mapping and observed their spatial separation into two opposite transverse directions that depended on the valley index of the excitons. Our theoretical simulations reproduced the salient features of these observations. Our demonstration of the robust interlayer exciton VHE at room temperature, enabled by their intrinsically long lifetimes, will open up realistic possibilities for the development of opto-valleytronic devices based on TMD heterostructures. |
| first_indexed | 2024-10-01T07:16:50Z |
| format | Journal Article |
| id | ntu-10356/147882 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:16:50Z |
| publishDate | 2021 |
| record_format | dspace |
| spelling | ntu-10356/1478822023-02-28T20:03:38Z Robust room temperature valley Hall effect of interlayer excitons Huang, Zumeng Liu, Yuanda Dini, Kévin Tan, Qinghai Liu, Zhuojun Fang, Hanlin Liu, Jin Liew, Timothy Gao, Weibo School of Physical and Mathematical Sciences Physics and Applied Physics The Photonics Institute Centre for Disruptive Photonic Technologies (CDPT) Science::Physics::Optics and light TMD Heterostructures Interlayer Excitons The Berry curvature in the band structure of transition metal dichalcogenides (TMDs) introduces a valley-dependent effective magnetic field, which induces the valley Hall effect (VHE). Similar to the ordinary Hall effect, the VHE spatially separates carriers or excitons, depending on their valley index, and accumulates them at opposite sample edges. The VHE can play a key role in valleytronic devices, but previous observations of the VHE have been limited to cryogenic temperatures. Here, we report a demonstration of the VHE of interlayer excitons in a MoS2/WSe2 heterostructure at room temperature. We monitored the in-plane propagation of interlayer excitons through photoluminescence mapping and observed their spatial separation into two opposite transverse directions that depended on the valley index of the excitons. Our theoretical simulations reproduced the salient features of these observations. Our demonstration of the robust interlayer exciton VHE at room temperature, enabled by their intrinsically long lifetimes, will open up realistic possibilities for the development of opto-valleytronic devices based on TMD heterostructures. Ministry of Education (MOE) National Research Foundation (NRF) We acknowledge the support from the Singapore National Research Foundation (NRF-NRFF2015-03) and its Competitive Research Program (CRP Award NRF-CRP21-2018- 0007), Singapore Ministry of Education (MOE2016-T2-2- 077, MOE2016-T2-1-163, MOE2016-T3-1-006 (S)), and A*Star QTE programme. T.L. and K.D. were supported by the Singapore Ministry of Education (MOE2017-T2-1-001 and MOE2018-T3-1-002). The work done at Sun Yat-sen University was supported by the National Key R&D Program of China (2018YFA0306100), the National Natural Science Foundation of China (11874437), Guangzhou Science and Technology Project (201805010004) and the Natural Science Foundation of Guangdong (2018B030311027). We thank J. Kono for the helpful discussion. 2021-04-14T06:36:22Z 2021-04-14T06:36:22Z 2020 Journal Article Huang, Z., Liu, Y., Dini, K., Tan, Q., Liu, Z., Fang, H., Liu, J., Liew, T. & Gao, W. (2020). Robust room temperature valley Hall effect of interlayer excitons. Nano Letters, 20(2), 1345-1351. https://dx.doi.org/10.1021/acs.nanolett.9b04836 1530-6984 https://hdl.handle.net/10356/147882 10.1021/acs.nanolett.9b04836 2 20 1345 1351 en NRF-NRFF2015-03 NRF-CRP21-2018-0007 MOE2016-T2-2-077 MOE2016-T2-2-077 MOE2016-T3-1-006 (S) Nano Letters 10.21979/N9/Q9MC8W This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.nanolett.9b04836. application/pdf |
| spellingShingle | Science::Physics::Optics and light TMD Heterostructures Interlayer Excitons Huang, Zumeng Liu, Yuanda Dini, Kévin Tan, Qinghai Liu, Zhuojun Fang, Hanlin Liu, Jin Liew, Timothy Gao, Weibo Robust room temperature valley Hall effect of interlayer excitons |
| title | Robust room temperature valley Hall effect of interlayer excitons |
| title_full | Robust room temperature valley Hall effect of interlayer excitons |
| title_fullStr | Robust room temperature valley Hall effect of interlayer excitons |
| title_full_unstemmed | Robust room temperature valley Hall effect of interlayer excitons |
| title_short | Robust room temperature valley Hall effect of interlayer excitons |
| title_sort | robust room temperature valley hall effect of interlayer excitons |
| topic | Science::Physics::Optics and light TMD Heterostructures Interlayer Excitons |
| url | https://hdl.handle.net/10356/147882 |
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