Unconventional Transverse Transport above and below the Magnetic Transition Temperature in Weyl Semimetal EuCd_{2}As_{2}

Y Xu; L Das; J Z Ma; C J Yi; S M Nie; Y G Shi; A Tiwari; S S Tsirkin; T Neupert; M Medarde; M Shi; J Chang; T Shang

doi:10.1103/PhysRevLett.126.076602

Unconventional Transverse Transport above and below the Magnetic Transition Temperature in Weyl Semimetal EuCd_{2}As_{2}

Phys Rev Lett. 2021 Feb 19;126(7):076602. doi: 10.1103/PhysRevLett.126.076602.

Authors

Y Xu¹, L Das¹, J Z Ma^{2

3}, C J Yi⁴, S M Nie⁵, Y G Shi^{4

6}, A Tiwari^{1

7}, S S Tsirkin¹, T Neupert¹, M Medarde⁸, M Shi³, J Chang¹, T Shang^{1

8

9}

Affiliations

¹ Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
² Department of Physics, City University of Hong Kong, Kowloon, Hong Kong.
³ Swiss Light Source, Paul Scherrer Institut, Villigen CH-5232, Switzerland.
⁴ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
⁵ Department of Materials Science and Engineering, Stanford University, Stanford, California 94035, USA.
⁶ Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
⁷ Condensed Matter Theory Group, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.
⁸ Laboratory for Multiscale Materials Experiments, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.
⁹ Key Laboratory of Polar Materials and Devices (MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China.

PMID: 33666464
DOI: 10.1103/PhysRevLett.126.076602

Abstract

As exemplified by the growing interest in the quantum anomalous Hall effect, the research on topology as an organizing principle of quantum matter is greatly enriched from the interplay with magnetism. In this vein, we present a combined electrical and thermoelectrical transport study on the magnetic Weyl semimetal EuCd_{2}As_{2}. Unconventional contribution to the anomalous Hall and anomalous Nernst effects were observed both above and below the magnetic transition temperature of EuCd_{2}As_{2}, indicating the existence of significant Berry curvature. EuCd_{2}As_{2} represents a rare case in which this unconventional transverse transport emerges both above and below the magnetic transition temperature in the same material. The transport properties evolve with temperature and field in the antiferromagnetic phase in a different manner than in the paramagnetic phase, suggesting different mechanisms to their origin. Our results indicate EuCd_{2}As_{2} is a fertile playground for investigating the interplay between magnetism and topology, and potentially a plethora of topologically nontrivial phases rooted in this interplay.