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Talks and Poster Presentations (without Proceedings-Entry):

Sami Dzsaber, L. Prochaska, A. Sidorenko, Gaku Eguchi, R. Svagera, M. Waas, A. Prokofiev, K. Hradil, Q. Si, S. Paschen:
"Tuning spin-orbit coupling in the Kondo insulator Ce3Bi4Pt3";
Poster: Int. Conference on Strongly Correlated Electron systems, SCES2017, Prague, CZ; 2017-07-17 - 2017-07-21.



English abstract:
The recent discovery of topologically non-trivial bandstructures in weakly correlated band insulators [1] has
triggered enormous efforts in the search for their strongly correlated counterparts. A highly suitable setting for
investigating the interplay between strong electron correlations and topology are (rare earth-based) heavy fermion
systems where there is no doubt about the key role of strong correlations at low temperatures. It is also well
established that the 4f electrons of the rare earth elements in these systems experience strong spin-orbit coupling.
This has led to the suggestion that topological Kondo insulators may exist [2]. The spin-orbit interaction among the
conduction electrons (lSO) in these systems has received comparably little attention [3]. It is at focus in the present
work where we introduce, for the first time, lSO as systematic experimental tuning parameter in a Kondo insulator
[4]. We have grown a series of Ce3Bi4(Pt1-xPdx)3 single crystals [4] of the archetypal cubic non-centrosymmetric
Kondo insulator Ce3Bi4Pt3 [5,6]. The substitution series is iso-structural, iso-electronic, and iso-size, and thus
doping and (chemical) pressure tuning effects should be minimal. The Kondo insulator to semimetal transition that
we observe with increasing Pd content must thus be attributed to a decrease of lSO upon successively replacing the
heavy 5d element Pt by the much lighter 4d element Pd. The low-temperature electronic specific heat coefficient
Cel/T of Ce3Bi4Pd3 is linear in T 2, with a slope that is sizably larger than any phonon contribution. This is the
hallmark of a strongly correlated system with linear electronic dispersion, as the recently predicted Weyl-Kondo
semimetal [7].
We gratefully acknowledge financial support from the Austrian Science Fund (doctoral program W1243 and I2535-
N27) and the U.S. Army Research Office (ARO Grant No.W911NF-14-1-0496) in Vienna, and the ARO (Grant
No.W911NF-14-1-0525) and the Robert A. Welch Foundation (Grant No. C-1411) at Rice.
[1] A. Bansil, H. Lin, and T. Das, Rev. Mod. Phys. 88, 021004 (2016).
[2] M. Dzero, J. Xia, V. Galitski and P. Coleman, Rev. Condens. Matter. Phys, 7, 249 (2016).
[3] X.-Y. Feng, J. Dai, C.-H. Chung, and Q. Si, Phys. Rev. Lett., 111, 016402 (2013).
[4] S. Dzsaber, L. Prochaska, A. Sidorenko, G. Eguchi, R. Svagera, M. Waas, A. Prokofiev, Q. Si, and S. Paschen,
"Tuning spin-orbit coupling in the Kondo insulator Ce3Bi4Pt3 by Pd substitution" arXiv:1612.03972 (2016).
[5] M.F. Hundley, P. C. Canfield, J. D. Thompson, Z. Fisk, and J. M. Lawrence Phys. Rev. B 42, 6842 (1990).
[6] M. Jaime, R. Movshovich, G. Stewart, W. Beyermann, M. Berisso, M. Hundley, P. Canfield, and J. Sarrao,
Nature, 45, 160 (2000).
[7] H.-H. Lai, S. E. Grefe, S. Paschen, and Q. Si, "Weyl-Kondo semimetal in a heavy fermion system",
arXiv:1612.03899 (2016).
E-mail for corresponding author: dzsaber@ifp.tuwien.ac.at

Keywords:
Kondo, Weyl, spin orbit

Created from the Publication Database of the Vienna University of Technology.