Negligible Hall resistance in Dirac semimetal EuCu₂Sb₂

Magnetic Dirac semimetal is of great interest among researchers these days. Many of these Dirac semimetals are protected by the combination of crystal symmetries and a special antiferromagnetic time-reversal symmetry ^[1]. There are limited systems that show magnetic Dirac state. Recently, the EuCd₂As₂ compound has been identified as magnetic Weyl semimetal ^[2]. A single crystal of EuCu₂Sb₂ was synthesized by flux growth method using Cu-Sb flux. The crystal structure of EuCu2Sb2 contains a subsequent magnetic Eu²⁺ and non-magnetic [Cu₂Sb₂]^2- layers perpendicular to c- axis, and Eu moments align in antiferromagnetically between two adjacent layers. Electrical resistivity and specific heat data show antiferromagnetic transition at 5.1 K. Interestingly, it shows negligible Hall resistance with the applied magnetic field 0 – 14 T. In Angle-resolved photoemission spectroscopy measurement, the linear band crossing near the Fermi level suggests Dirac like band dispersion which results in unconventional Hall resistance.

[1] Young, Steve M. and Wieder, Benjamin J., Phys. Rev. Lett. 118, 186401 (2017).

[2] Soh, J.-R. et al., Phys. Rev. B 100, 201102 (2019).