Exploring spin-canting in the Dirac semimetal, Ca<sub>1-<i>x</i></sub>Na<i><sub>x</sub></i>MnBi<sub>2</sub>,<sub> </sub>with neutron diffraction measurements<sub>.</sub>

ORAL

Abstract

Recent optical and magnetic torque measurements of Ca1-xNaxMnBi2 suggested that the observed anomalous behavior in their dc resistivity at temperatures below the antiferromagnetic transition is consistent with the canting of the Manganese ordered moments [1]. Spin canting in the 112 families of Dirac semimetals is interesting because it can lead to the type-II Weyl state as a consequence of time-reversal symmetry breaking. However, previously reported canting driven Weyl states in other members, such as YbMnBi2 [1], are controversial and refuted by neutron diffraction measurements. To understand whether the spin-canting is behind the anomalous resistivity bump, we performed neutron diffraction measurements on two members of Ca1-xNaxMnBi2, x = 0 and 0.05. I will discuss the observed superstructure peaks, which appear consistent with the resistivity bump, in the framework of the spin canting. The result is important because it suggests Ca1-xNaxMnBi2 as a rare member of 112 Dirac semimetals with the possibility of type-II Weyl state. [1] R. Yang et. al PRL 124,137201 (2020).

*Work at BNL was supported by Office of BES, U.S. DOE under Contract No. DE-SC0012704. We acknowledge the support of the NIST, U.S. DOC, in providing the neutron research facilities used in this work.

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Presenters

  • Aashish Sapkota

    • Brookhaven National Laboratory
    • Ames Laboratory and Iowa State University, Ames, IA USA 50011

Authors

  • Aashish Sapkota

    • Brookhaven National Laboratory
    • Ames Laboratory and Iowa State University, Ames, IA USA 50011

  • Igor Zaliznyak

    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory

  • John Tranquada

    • Brookhaven National Laboratory
    • Brookhaven national lab
    • Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory

  • Cedomir Petrovic

    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory
    • CMPMS Department, Brookhaven National Laboratory

  • Zhijun Xu

    • National Institute of Standards and Technology
    • NIST and University of Maryland
    • NIST Center for Neutron research, National Institute of Standards and Technology
    • NIST Center for Neutron Research
    • University of Maryland
    • NIST Center for Neutron Research, NIST

  • Guangyong Xu

    • NIST
    • NIST Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standard and Technology
    • Center for Neutron Research, National Institute of Standards and Technology
    • National Institute of Standards and Technology
    • Center of Neutron Research, National Institute of Standards and Technology, NIST
    • NIST Center for Neutron Research, NIST

  • Yangmu Li

    • Brookhaven National Laboratory
    • Condensed Matter Physics and Materials Science Division, Brookhaven National Laboratory