Fingerprints of inelastic transport at the surface of the topological insulator Bi 2 Se 3 : role of electron-phonon coupling
Costache, Marius Vasile (Institut Català de Nanociència i Nanotecnologia)
Neumann, Ingmar (Institut Català de Nanociència i Nanotecnologia)
Sierra, Juan F. (Institut Català de Nanociència i Nanotecnologia)
Marinova, Vera (Bulgarian Academy of Sciences. Institute of Optical Materials and Technologies)
Gospodinov, M. M. (Bulgarian Academy of Sciences. Institute of Solid State Physics)
Roche, Stephan (Institut Català de Nanociència i Nanotecnologia)
Valenzuela, Sergio O. (Institut Català de Nanociència i Nanotecnologia)

Date:	2014
Abstract:	We report on electric-field and temperature-dependent transport measurements in exfoliated thin crystals of the Bi2Se3 topological insulator. At low temperatures (<50 K) and when the chemical potential lies inside the bulk gap, the crystal resistivity is strongly temperature dependent, reflecting inelastic scattering due to the thermal activation of optical phonons. A linear increase of the current with voltage is obtained up to a threshold value at which current saturation takes place. We show that the activated behavior, the voltage threshold, and the saturation current can all be quantitatively explained by considering a single optical-phonon mode with energy â Ω≈8 meV. This phonon mode strongly interacts with the surface states of the material and represents the dominant source of scattering at the surface at high electric fields.
Grants:	European Commission 308023 Ministerio de Economía y Competitividad MAT2012-33911 Ministerio de Economía y Competitividad RYC-2011-08319 Ministerio de Economía y Competitividad MAT2010-18065
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Published in:	Physical review letters, Vol. 112, issue 8 (Feb. 2014) , art. 86601, ISSN 1079-7114

DOI: 10.1103/PhysRevLett.112.086601

Postprint 12 p, 487.8 KB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles