Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 37: Topological Semimetals - Theory (joint session TT/MA)

TT 37.7: Vortrag

Mittwoch, 3. April 2019, 11:15–11:30, H22

Tuning the anomalous Hall effect in topological magnets via the Berry curvature design — •Kaustuv Manna, Lukas Muechler, Ting Hui Kao, Rolf Stinshoff, Nitesh Kumar, Jürgen Kübler, Chandra Shekhar, Yan Sun, and Claudia Felser — Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany

For a long time anomalous Hall effect (AHE) has been considered as one of the characteristic signature of finite spontaneous magnetization in a material. It was considered to scale with sample's magnetization. However, the recent realization of the connection between the intrinsic AHE and the Berry curvature predicts other possibilities. AHE is an excellent method to understand the effect of various topological states and the Berry phase on the physical properties of material. Depending on the details of the band structure, the Hall conductivity can take a colossal value or even zero, independent of the corresponding magnetization of the sample. As a case study, we illustrate the situation in the Heusler compounds where one can easily tune the band structure by engineering the crystal symmetry and composition. With experimental evidences, we demonstrate how the Hall conductivity can be tuned from 0 to 2000 Ω-1cm-1 without disturbing sample's magnetization. With the help of the theoretical band structure calculations and ARPES data, we discover the first topological magnet with giant anomalous Hall conductivity (~ 1700 Ω-1cm-1) and an exceptionally high anomalous Hall angle up to 12% in a topological magnetic Heusler.