Unveiling surface and bulk contributions in temperature dependent THz emission from Bi2Te3
We report evolution of the pulsed terahertz (THz) emission from Bi _2 Te _3 topological insulator in a wide temperature range, where an interplay between the topological surface and bulk contributions can be addressed in a distinguishable manner. A circular photogalvanic effect-induced topological s...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/ad345a |
| _version_ | 1797244418251554816 |
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| author | Anand Nivedan Sunil Kumar |
| author_facet | Anand Nivedan Sunil Kumar |
| author_sort | Anand Nivedan |
| collection | DOAJ |
| description | We report evolution of the pulsed terahertz (THz) emission from Bi _2 Te _3 topological insulator in a wide temperature range, where an interplay between the topological surface and bulk contributions can be addressed in a distinguishable manner. A circular photogalvanic effect-induced topological surface current contribution to THz generation can be clearly identified in the signal, otherwise, overwhelmed by the hot carrier decoherence in the bulk states. With the decreasing temperature, an initial sharp increase in the topological surface THz signal is observed before it attains a constant value below ∼200 K. The scattering channels between topological surface and bulk regions via carrier-phonon scattering are dominantly active only above the bulk-Debye temperature of ∼180 K, and the temperature-independent behavior of it at lower temperatures is indicative of robust nature of topological surface states. THz emission due to ultrafast photon-drag current in the bulk states is almost independent of temperature in the entire range, while the combined photo-Dember and band-bending effects induced photocurrent is doubled at 10 K. |
| first_indexed | 2024-04-24T19:10:41Z |
| format | Article |
| id | doaj.art-633d030366bd476ba6c437aa0718d9a5 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-04-24T19:10:41Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-633d030366bd476ba6c437aa0718d9a52024-03-26T10:20:05ZengIOP PublishingNew Journal of Physics1367-26302024-01-0126303304410.1088/1367-2630/ad345aUnveiling surface and bulk contributions in temperature dependent THz emission from Bi2Te3Anand Nivedan0Sunil Kumar1https://orcid.org/0000-0002-1065-9883Femtosecond Spectroscopy and Nonlinear Photonics Laboratory, Department of Physics, Indian Institute of Technology Delhi , Hauz Khas, New Delhi 110016, IndiaFemtosecond Spectroscopy and Nonlinear Photonics Laboratory, Department of Physics, Indian Institute of Technology Delhi , Hauz Khas, New Delhi 110016, IndiaWe report evolution of the pulsed terahertz (THz) emission from Bi _2 Te _3 topological insulator in a wide temperature range, where an interplay between the topological surface and bulk contributions can be addressed in a distinguishable manner. A circular photogalvanic effect-induced topological surface current contribution to THz generation can be clearly identified in the signal, otherwise, overwhelmed by the hot carrier decoherence in the bulk states. With the decreasing temperature, an initial sharp increase in the topological surface THz signal is observed before it attains a constant value below ∼200 K. The scattering channels between topological surface and bulk regions via carrier-phonon scattering are dominantly active only above the bulk-Debye temperature of ∼180 K, and the temperature-independent behavior of it at lower temperatures is indicative of robust nature of topological surface states. THz emission due to ultrafast photon-drag current in the bulk states is almost independent of temperature in the entire range, while the combined photo-Dember and band-bending effects induced photocurrent is doubled at 10 K.https://doi.org/10.1088/1367-2630/ad345aTHz emissiontime-domain spectroscopybismuth telluridelow-temperature physics |
| spellingShingle | Anand Nivedan Sunil Kumar Unveiling surface and bulk contributions in temperature dependent THz emission from Bi2Te3 New Journal of Physics THz emission time-domain spectroscopy bismuth telluride low-temperature physics |
| title | Unveiling surface and bulk contributions in temperature dependent THz emission from Bi2Te3 |
| title_full | Unveiling surface and bulk contributions in temperature dependent THz emission from Bi2Te3 |
| title_fullStr | Unveiling surface and bulk contributions in temperature dependent THz emission from Bi2Te3 |
| title_full_unstemmed | Unveiling surface and bulk contributions in temperature dependent THz emission from Bi2Te3 |
| title_short | Unveiling surface and bulk contributions in temperature dependent THz emission from Bi2Te3 |
| title_sort | unveiling surface and bulk contributions in temperature dependent thz emission from bi2te3 |
| topic | THz emission time-domain spectroscopy bismuth telluride low-temperature physics |
| url | https://doi.org/10.1088/1367-2630/ad345a |
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