Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical Thickness
Mercury telluride (HgTe) thin films with a critical thickness of 6.5 nm are predicted to possess a gapless Dirac-like band structure. We report a comprehensive study on gated and optically doped samples by magnetooptical spectroscopy in the THz range. The quasi-classical analysis of the cyclotron re...
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MDPI AG
2022-07-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/12/14/2492 |
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| author | Alexey Shuvaev Vlad Dziom Jan Gospodarič Elena G. Novik Alena A. Dobretsova Nikolay N. Mikhailov Ze Don Kvon Andrei Pimenov |
| author_facet | Alexey Shuvaev Vlad Dziom Jan Gospodarič Elena G. Novik Alena A. Dobretsova Nikolay N. Mikhailov Ze Don Kvon Andrei Pimenov |
| author_sort | Alexey Shuvaev |
| collection | DOAJ |
| description | Mercury telluride (HgTe) thin films with a critical thickness of 6.5 nm are predicted to possess a gapless Dirac-like band structure. We report a comprehensive study on gated and optically doped samples by magnetooptical spectroscopy in the THz range. The quasi-classical analysis of the cyclotron resonance allowed the mapping of the band dispersion of Dirac charge carriers in a broad range of electron and hole doping. A smooth transition through the charge neutrality point between Dirac holes and electrons was observed. An additional peak coming from a second type of holes with an almost density-independent mass of around <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.04</mn><msub><mi>m</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula> was detected in the hole-doping range and attributed to an asymmetric spin splitting of the Dirac cone. Spectroscopic evidence for disorder-induced band energy fluctuations could not be detected in present cyclotron resonance experiments. |
| first_indexed | 2024-03-09T10:14:03Z |
| format | Article |
| id | doaj.art-09df6ad60cc34453b96198370fc41fc9 |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-09T10:14:03Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-09df6ad60cc34453b96198370fc41fc92023-12-01T22:31:30ZengMDPI AGNanomaterials2079-49912022-07-011214249210.3390/nano12142492Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical ThicknessAlexey Shuvaev0Vlad Dziom1Jan Gospodarič2Elena G. Novik3Alena A. Dobretsova4Nikolay N. Mikhailov5Ze Don Kvon6Andrei Pimenov7Institute of Solid State Physics, Vienna University of Technology, 1040 Vienna, AustriaInstitute of Science and Technology Austria, 3400 Klosterneuburg, AustriaInstitute of Solid State Physics, Vienna University of Technology, 1040 Vienna, AustriaInstitute of Theoretical Physics, Technische Universität Dresden, 01062 Dresden, GermanyRzhanov Institute of Semiconductor Physics, 630090 Novosibirsk, RussiaRzhanov Institute of Semiconductor Physics, 630090 Novosibirsk, RussiaRzhanov Institute of Semiconductor Physics, 630090 Novosibirsk, RussiaInstitute of Solid State Physics, Vienna University of Technology, 1040 Vienna, AustriaMercury telluride (HgTe) thin films with a critical thickness of 6.5 nm are predicted to possess a gapless Dirac-like band structure. We report a comprehensive study on gated and optically doped samples by magnetooptical spectroscopy in the THz range. The quasi-classical analysis of the cyclotron resonance allowed the mapping of the band dispersion of Dirac charge carriers in a broad range of electron and hole doping. A smooth transition through the charge neutrality point between Dirac holes and electrons was observed. An additional peak coming from a second type of holes with an almost density-independent mass of around <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0.04</mn><msub><mi>m</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula> was detected in the hole-doping range and attributed to an asymmetric spin splitting of the Dirac cone. Spectroscopic evidence for disorder-induced band energy fluctuations could not be detected in present cyclotron resonance experiments.https://www.mdpi.com/2079-4991/12/14/2492Dirac fermionstopological insulatorsband structurequantum wellscyclotron resonance |
| spellingShingle | Alexey Shuvaev Vlad Dziom Jan Gospodarič Elena G. Novik Alena A. Dobretsova Nikolay N. Mikhailov Ze Don Kvon Andrei Pimenov Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical Thickness Nanomaterials Dirac fermions topological insulators band structure quantum wells cyclotron resonance |
| title | Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical Thickness |
| title_full | Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical Thickness |
| title_fullStr | Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical Thickness |
| title_full_unstemmed | Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical Thickness |
| title_short | Band Structure Near the Dirac Point in HgTe Quantum Wells with Critical Thickness |
| title_sort | band structure near the dirac point in hgte quantum wells with critical thickness |
| topic | Dirac fermions topological insulators band structure quantum wells cyclotron resonance |
| url | https://www.mdpi.com/2079-4991/12/14/2492 |
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