paper

Anisotropy of the magnetic and transport properties in EuZn $_{2}$ As $_{2}$

arXiv:2202.09963 · doi:10.1103/PhysRevB.105.165122

Abstract

Several recent studies have shown that the anisotropy in the magnetic structure of \ECA\ plays a significant role in stabilizing the Weyl nodes. To investigate the relationship between magnetic anisotropy and Weyl physics, we present a comparative study between EuZn $_{2}$ As $_{2}$ and EuCd $_{2}$ As $_{2}$ that are isostructural but with different magnetic anisotropy. We performed structural analysis, electronic transport, and magnetization experiments on millimeter-sized single crystals of EuZn $_{2}$ As $_{2}$ , and compared the results to those of EuCd $_{2}$ As $_{2}$ . By combining the first principle calculations and neutron diffraction experiment, we identify the magnetic ground state of EuZn $_{2}$ As $_{2}$ as A-type antiferromagnetic order with a transition temperature ( $T_{N}$ = 19.6 K) twice that of EuCd $_{2}$ As $_{2}$ . Like EuCd $_{2}$ As $_{2}$ , the negative magnetoresistance of EuZn $_{2}$ As $_{2}$ is observed after suppressing the resistivity peak at $T_{N}$ with increasing fields. However, the anisotropy in both transport and magnetization are much reduced in EuZn $_{2}$ As $_{2}$ . The difference could be ascribed to the weaker spin-orbit coupling, more localized $d$ -orbitals, and a larger contribution from the Eu $s$ -orbitals in the zinc compound, as suggested by the electronic band calculations. The same band structure effect could be also responsible for the observation of a smaller non-linear anomalous Hall effect in EuZn $_{2}$ As $_{2}$ compared to EuCd $_{2}$ As $_{2}$ .

Anisotropy of the magnetic and transport properties in EuZn2​As2​

Abstract

Anisotropy of the magnetic and transport properties in EuZn $_{2}$ As $_{2}$