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Alexander-Webber JA, Huang J, Beilsten-Edmands J, Čermák P, Drašar Č, Nicholas RJ, Coldea AI. Multi-band magnetotransport in exfoliated thin films of Cu x Bi 2Se 3. J Phys Condens Matter 2018; 30:155302. [PMID: 29469818 DOI: 10.1088/1361-648x/aab193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We report magnetotransport studies in thin (<100 nm) exfoliated films of Cu x Bi2Se3 and we detect an unusual electronic transition at low temperatures. Bulk crystals show weak superconductivity with [Formula: see text] K and a possible electronic phase transition around 200 K. Following exfoliation, superconductivity is supressed and a strongly temperature dependent multi-band conductivity is observed for T < 30 K. This transition between competing conducting channels may be enhanced due to the presence of electronic ordering, and could be affected by the presence of an effective internal stress due to Cu intercalation. By fitting to the weak antilocalisation conductivity correction at low magnetic fields we confirm that the low temperature regime maintains a quantum phase coherence length [Formula: see text] nm indicating the presence of topologically protected surface states.
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Affiliation(s)
- J A Alexander-Webber
- Department of Engineering, University of Cambridge, 9 J.J. Thomson Avenue, Cambridge CB3 0FA, United Kingdom
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Ohnoutek L, Hakl M, Veis M, Piot BA, Faugeras C, Martinez G, Yakushev MV, Martin RW, Drašar Č, Materna A, Strzelecka G, Hruban A, Potemski M, Orlita M. Strong interband Faraday rotation in 3D topological insulator Bi2Se3. Sci Rep 2016; 6:19087. [PMID: 26750455 PMCID: PMC4707504 DOI: 10.1038/srep19087] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/02/2015] [Indexed: 11/26/2022] Open
Abstract
The Faraday effect is a representative magneto-optical phenomenon, resulting from the transfer of angular momentum between interacting light and matter in which time-reversal symmetry has been broken by an externally applied magnetic field. Here we report on the Faraday rotation induced in the prominent 3D topological insulator Bi2Se3 due to bulk interband excitations. The origin of this non-resonant effect, extraordinarily strong among other non-magnetic materials, is traced back to the specific Dirac-type Hamiltonian for Bi2Se3, which implies that electrons and holes in this material closely resemble relativistic particles with a non-zero rest mass.
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Affiliation(s)
- L Ohnoutek
- Institute of Physics, Charles University, Ke Karlovu 5, CZ-121 16 Praha 2, Czech Republic
| | - M Hakl
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - M Veis
- Institute of Physics, Charles University, Ke Karlovu 5, CZ-121 16 Praha 2, Czech Republic
| | - B A Piot
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - C Faugeras
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - G Martinez
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - M V Yakushev
- Department of Physics, SUPA, Strathclyde University, G4 0NG Glasgow, UK.,Ural Federal University and Institute of Solid State Chemistry of RAS, Ekaterinburg, 620002, Russia
| | - R W Martin
- Department of Physics, SUPA, Strathclyde University, G4 0NG Glasgow, UK
| | - Č Drašar
- Institute of Applied Physics and Mathematics, Faculty of Chemical Technology, University of Pardubice, Studentská 84, 532 10 Pardubice, Czech Republic
| | - A Materna
- Institute of Electronic Materials Technology, ul. Wolczynska 133, PL 01-919 Warsaw, Poland
| | - G Strzelecka
- Institute of Electronic Materials Technology, ul. Wolczynska 133, PL 01-919 Warsaw, Poland
| | - A Hruban
- Institute of Electronic Materials Technology, ul. Wolczynska 133, PL 01-919 Warsaw, Poland
| | - M Potemski
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - M Orlita
- Institute of Physics, Charles University, Ke Karlovu 5, CZ-121 16 Praha 2, Czech Republic.,Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
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Orlita M, Piot BA, Martinez G, Kumar NKS, Faugeras C, Potemski M, Michel C, Hankiewicz EM, Brauner T, Drašar Č, Schreyeck S, Grauer S, Brunner K, Gould C, Brüne C, Molenkamp LW. Magneto-optics of massive dirac fermions in bulk Bi2Se3. Phys Rev Lett 2015; 114:186401. [PMID: 26001011 DOI: 10.1103/physrevlett.114.186401] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Indexed: 05/27/2023]
Abstract
We report on magneto-optical studies of Bi2Se3, a representative member of the 3D topological insulator family. Its electronic states in bulk are shown to be well described by a simple Dirac-type Hamiltonian for massive particles with only two parameters: the fundamental band gap and the band velocity. In a magnetic field, this model implies a unique property-spin splitting equal to twice the cyclotron energy: Es=2Ec. This explains the extensive magnetotransport studies concluding a fortuitous degeneracy of the spin and orbital split Landau levels in this material. The Es=2Ec match differentiates the massive Dirac electrons in bulk Bi2Se3 from those in quantum electrodynamics, for which Es=Ec always holds.
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Affiliation(s)
- M Orlita
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
- Institute of Physics, Charles University in Prague, CZ-12116 Prague, Czech Republic
| | - B A Piot
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - G Martinez
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - N K Sampath Kumar
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - C Faugeras
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - M Potemski
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25, avenue des Martyrs, 38042 Grenoble, France
| | - C Michel
- Institute for Theoretical Physics, TP IV, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - E M Hankiewicz
- Institute for Theoretical Physics, TP IV, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - T Brauner
- Institute for Theoretical Physics, Vienna University of Technology, A-1040 Vienna, Austria
| | - Č Drašar
- Faculty of Chemical Technology, University of Pardubice, CZ-53210 Pardubice, Czech Republic
| | - S Schreyeck
- Physikalisches Institut (EP III), Universität Würzburg, D-97074 Würzburg, Germany
| | - S Grauer
- Physikalisches Institut (EP III), Universität Würzburg, D-97074 Würzburg, Germany
| | - K Brunner
- Physikalisches Institut (EP III), Universität Würzburg, D-97074 Würzburg, Germany
| | - C Gould
- Physikalisches Institut (EP III), Universität Würzburg, D-97074 Würzburg, Germany
| | - C Brüne
- Physikalisches Institut (EP III), Universität Würzburg, D-97074 Würzburg, Germany
| | - L W Molenkamp
- Physikalisches Institut (EP III), Universität Würzburg, D-97074 Würzburg, Germany
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