The effects of strain on the topology of EuCd<sub>2</sub>As<sub>2</sub>

ORAL

Abstract

EuCd2As2 is well known for its Dirac point (DP) close to the Fermi surface. Consequently, there has been a lot of research regarding the splitting of this DP into a single pair of Weyl points (WP) mostly in the antiferromagnetic (AFM) order. Recently, there has been evidence for possible paramagnetic states with ferromagnetic (FM) spin fluctuations. Furthermore, the effects of strain on this structure remained open. Using ab-initio DFT calculations, we show the effects of strain on the AFM and FM ordered EuCd2As2. The non-strained structure shows a DP close to the Fermi surface protected by C3 symmetry. Applying strain to this compound while preserving this symmetry, allows for shifting the DP along the kz axis. By the analysis with a low-energy effective Hamiltonian, we calculate the topological properties as a function of strain.

*Funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) within the SFB/transregio 288 “Elastic Tuning and Response of Electronic Quantum Phases of Matter” (ELASTO-Q-MAT), project B05 "Correlations and relativistic effects in elastic tunable electronic systems" is gratefully acknowledged.

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Presenters

  • Adrian Valadkhani

    • Goethe University Frankfurt

Authors

  • Adrian Valadkhani

    • Goethe University Frankfurt

  • Young-Joon Song

    • Goethe University Frankfurt

  • Roser Valenti

    • Goethe University Frankfurt
    • Goethe-Universität Frankfurt
    • Goethe University Frankfurt am Main
    • ITP, Goethe University Frankfurt
    • Institute for Theoretical Physics, Goethe-Universitat Frankfurt
    • Goethe-University Frankfurt
    • Institut für Theoretische Physik, Goethe University Frankfurt