Dresden 2014 – scientific programme
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O: Fachverband Oberflächenphysik
O 35: Transport: Topological Insulators I (TT jointly with O)
O 35.4: Talk
Tuesday, April 1, 2014, 14:45–15:00, HSZ 304
Photoemission investigation of the predicted topological Kondo insulator behavior of SmB6 — •Peter Hlawenka1, Emile Rienks1, Konrad Siemensmeyer1, Eugen Weschke1, Andrei Varykhalov1, Natalya Shitsevalova2, Slavomir Gabani3, Karol Flachbart3, and Oliver Rader1 — 1Helmholtz-Zentrum Berlin — 2Institute for Problems of Material Science, Kiev, Ukraine — 3IEP, Slovak Academy of Science, Kosice
The system SmB6 is known for its unusual resistivity which increases exponentially
with decreasing temperature and saturates below 3 K [1].
This has recently been attributed to topological-Kondo-insulator behavior
where a topological surface state is created by Sm4f-5d hybridization
and is responsible for the transport [2].
The local-density-approximation + Gutzwiller calculations of the (100) surface
predict the appearance of three Dirac cones in the surface Brillouin zone [2].
We perform angle-resolved photoemission (ARPES) below 1 K and do not observe the predicted
Dirac cones at Γ or X.
Moreover, the Fermi surface is made up of steeply dispersing bulk Sm5d states.
The Sm2+ 4f band and the hybridization gaps where the surface
states are expected [2] are too far (∼20 meV) below the Fermi energy
in order to contribute to the transport.
These results will be discussed in comparison to other ARPES studies.
J. C. Cooley, M. C. Aronson, Z. Fisk, P. C. Canfield, Phys. Rev. Lett. 74, 1629 (1995)
F. Lu, J. Zhao, H. Weng, Z. Fang, Xi Dai, Phys. Rev. Lett. 110, 096401 (2013)