Regensburg 2019 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 5: Topological insulators
HL 5.9: Vortrag
Montag, 1. April 2019, 11:45–12:00, H36
Quantum oscillations of the Hall resistance in bulk Bi2Se3 at high temperatures — •Olivio Chiatti1, Marco Busch1, Sergio Pezzini2, Steffen Wiedmann2, Oliver Rader3, Lada V. Yashina4, and Saskia F. Fischer1 — 1Novel Materials Group, Humboldt-Universität zu Berlin, 10099 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
Bi2Se3 is one of the prototype three-dimensional (3D) topological insulators, where investigating transport by the two-dimensional (2D) topological surface states (TSS) has been hampered by residual bulk charge carriers.
In recent work, the high-field Hall resistance and low-field magnetoresistance indicate that the TSS may coexist with a layered 2D electronic system [1].
We have investigated nominally undoped, bulk Bi2Se3 with a high electron density n≈2·1019 cm−3 and show quantum oscillations of the Hall resistance for temperatures up to 50 K.
The angular and temperature dependence of the Hall resistance and the Shubnikov-de Haas oscillations show 3D and 2D contributions to transport.
Angular-resolved photoemission spectroscopy proves the existence of TSS.
We present a model for Bi2Se3 and suggest a coexistence of TSS and 2D layered transport stabilizing the quantum oscillations of the Hall resistance [2].
[1] Chiatti et al., Sci. Rep. 6, 27483 (2016).
[2] Busch et al., Sci. Rep. 8, 485 (2017).