Journal Article

FZJ-2016-07606

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Superparamagnetism-induced mesoscopic electron focusing in topological insulators

Sessi, P. (Corresponding author) ; Rüßmann, P.FZJ* ; Bathon, T. ; Barla, A. ; Kokh, K. A. ; Tereshchenko, O. E. ; Fauth, K. ; Mahatha, S. K. ; Valbuena, M. A. ; Godey, S. ; Glott, F. ; Mugarza, A. ; Gargiani, P. ; Valvidares, M. ; Long, N. H.FZJ* ; Carbone, C. ; Mavropoulos, P.FZJ* ; Blügel, S.FZJ* ; Bode, M.

2016
Inst. Woodbury, NY

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Please use a persistent id in citations: http://hdl.handle.net/2128/13269  doi:10.1103/PhysRevB.94.075137

Abstract: Recently it has been shown that surface magnetic doping of topological insulators induces backscattering of Dirac states which are usually protected by time-reversal symmetry [Sessi et al., Nat. Commun. 5, 5349 (2014)]. Here we report on quasiparticle interference measurements where, by improved Fermi level tuning, strongly focused interference patterns on surface Mn-doped Bi2Te3 could be directly observed by means of scanning tunneling microscopy at 4 K. Ab initio and model calculations reveal that their mesoscopic coherence relies on two prerequisites: (i) a hexagonal Fermi surface with large parallel segments (nesting) and (ii) magnetic dopants which couple to a high-spin state. Indeed, x-ray magnetic circular dichroism shows superparamagnetism even at very dilute Mn concentrations. Our findings provide evidence of strongly anisotropic Dirac-fermion-mediated interactions and demonstrate how spin information can be transmitted over long distances, allowing the design of experiments and devices based on coherent quantum effects in topological insulators.

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Contributing Institute(s):

1. Quanten-Theorie der Materialien (IAS-1)
2. Quanten-Theorie der Materialien (PGI-1)
3. JARA-FIT (JARA-FIT)
4. JARA - HPC (JARA-HPC)

Research Program(s):

1. 142 - Controlling Spin-Based Phenomena (POF3-142) (POF3-142)
2. 143 - Controlling Configuration-Based Phenomena (POF3-143) (POF3-143)
3. Scattering of topologically protected states off defects in topological insulators (jara0078_20131101) (jara0078_20131101)

Appears in the scientific report 2016

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Database coverage:
; ; ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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