Berlin 2018 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 7: Topological insulators I (joint session HL/TT)

HL 7.10: Vortrag

Montag, 12. März 2018, 12:00–12:15, A 151

High-temperature quantum oscillations of the Hall resistance in bulk Bi2Se3 — •Olivio Chiatti1, Marco Busch1, Sergio Pezzini2, Steffen Wiedmann2, Oliver Rader3, Lada V. Yashina4, and Saskia F. Fischer11Novel Materials Group, Humboldt-Universität zu Berlin, 12489 Berlin, Germany — 2High Field Magnet Laboratory, Radboud University Nijmegen, 6525ED Nijmegen, The Netherlands — 3Helmholtz-Zentrum-Berlin für Materialien und Energie, 12489 Berlin, Germany — 4Department of Chemistry, Moscow State University, 119991 Moscow, Russia

Protected topological surface states (TSS) with helically spin-polarized Dirac fermions (HSDF) are of high interest as a new state of quantum matter. Electronic bulk states in three-dimensional (3D) materials with TSS often mask the transport properties of HSDF. In recent work, the high-field Hall resistance and low-field magnetoresistance indicate that the TSS may coexist with a layered two-dimensional electronic system (2DES) [1]. Here, we demonstrate quantum oscillations of the Hall resistance for temperatures up to 50 K, in nominally undoped bulk Bi2Se3 with a high electron density n of about 2·1019 cm−3. From the angular and temperature dependence of the Hall resistance and the Shubnikov-de Haas oscillations we identify 3D and 2D contributions to transport. Angular resolved photoemission spectroscopy proves the existence of TSS. We present a model for Bi2Se3 and suggest that the coexistence of TSS and 2D layered transport stabilizes the quantum oscillations of the Hall resistance.
 [1] Chiatti et al., Sci. Rep. 6, 27483 (2016)

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