Special seminars TRR80

25.10.2017 4 p.m., room: R-242
Dr. Peter Milde (TU Dresden, Institute of Applied Physics, Dresden)
Scanning Force Microscopy Investigations of Skyrmions
26.10.2017 2 p.m., room: S-254
Prof. Dr. Vasily Moshnyaga (Georg-August-Universität Göttingen, Germany)
Order / disorder phenomena in perovskite films
14.11.2017 4 p.m., room: S-288
Dr. Martin Hohenadler (Universität Würzburg)
Competing Orders in Luttinger and Dirac Liquids
15.11.2017 3:30 p.m., room: S-403
Dr. Dirk Wulferding (Institute for Condensed Matter Physics, TU Braunschweig and Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science, POSTECH, Korea)
Magnetic force microscopy beyond imaging - from low energy condensed matter physics to high energy particle physics
28.11.2017 5 p.m., room: S-288
Prof. Dr. Björn Trauzettel (Universität Würzburg)
Chiral anomaly and fractional charges at the quantum spin Hall edge
30.11.2017 1:30 p.m., room: S-403
Dr. Leonid E. Svistov (P.L. Kapitza Institute for Physical Problems of Russian Academy of Sciences, Moscow)
Exotic phases in the triangular antiferromagnet CuCrO2
4.12.2017 12:15 p.m., room: S-439
Dr. Ivan Rungger (National Physics Laboratory, Teddington/London)
Beyond semi-local DFT corrections for nanoscale materials and device modelling
11.12.2017 3:45 p.m., room: S-288
Prof. Avinash Mahajan (Indian Institute of Technology Bombay, Mumbai)
Gapless spin liquid behaviour in the S = 1 honeycomb ruthenate Ag3LiRu2O6
23.1.2018 4 p.m., room: S-288
Dr. Achilleas Lazarides (Max-Planck-Institut für die Physik komplexer Systeme, Dresden)
Floquet many-body physics: Ensembles and order away from equilibrium
26.1.2018 10 a.m., room: S-403
Dr. Dávid Szaller (Institut für Festkörperphysik, TU Wien)
Exotic magnetoelectric excitations of the multiferroic SmFe3(BO3)4
30.1.2018 4 p.m., room: S-288
Dr. Andrés Cano (CNRS, Université Grenoble Alpes, Institut Néel, Grenoble and Department of Materials, ETH Zurich)
FeSi: A new building block for iron-based superconductivity

The discovery of superconductivity in F-doped LaFeAsO added a new exciting chapter to the venerable field of high-temperature superconductivity [1]. Since then, a number of iron-based superconductors have been found [2]. However, in all these superconductors the Fe atom is invariably associated to pnictogen or chalcogen elements (P, As and Se, Te respectively). This circumstance raises the important fundamental question about the link between Fe-based superconductivity and the apparent need of these pnictogens and chalcogens [3].

I will present the novel iron silicide LaFeSiH displaying superconductivity with onset at 11 K [4]. We find that this pnictogen-free compound is isostructural to LaFeAsO, with a similar low-temperature tetragonal to orthorhombic distortion. Using density functional theory we show that this system is also a multiband metal in which the orthorhombic distortion is likely related to single-stripe antiferromagnetic order. Electrical resistivity and magnetic susceptibility measurements reveal that these features occur side-by-side with superconductivity, which is suppressed by external pressure. [1] Y. Kamihara et al., Iron-based layered superconductor La[O1-xFx]FeAs (x=0.05-0.12) with Tc = 26 K, JACS 130, 3296 (2008) [2] H. Hosono et al., Exploration of new superconductors and functional materials, and fabrication of super-conducting tapes and wires of iron pnictides, Sci. Technol. Adv. Mater. 16, 033503 (2016). [3] D. Guterding et al., Nontrivial Role of Interlayer Cation States in Iron-Based Superconductors, PRL 118, 017204 (2017). [4] F. Bernardini, G. Garbarino, A. Sulpice, M. Núñez-Regueiro, E. Gaudin, B. Chevalier, M.-A. Méasson, A. Cano, and S. Tencé, Iron-based superconductivity extended to the novel silicid e hydride LaFeSiH, arXiv:1701.05010

27.2.2018 2 p.m., room: S-288
Prof. Dr. Shuichi Murakami (Tokyo Institute of Technology)
Topological phases in condensed matter