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arXiv · 1709.03394

Massive fermions with low mobility in antiferromagnet orthorhombic CuMnAs single crystals

Xiao Zhang·Shanshan Sun·Hechang Lei
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Abstract

We report the physical properties of orthorhombic o-CuMnAs single crystal, which is predicted to be a topological Dirac semimetal with magnetic ground state and inversion symmetry broken. o-CuMnAs exhibits an antiferromagnetic transition with TN ~ 312 K. Further characterizations of magnetic properties suggest that the AFM order may be canted with the spin orientation in the bc plane. Small isotropic MR and linearly field-dependent Hall resistivity with positive slope indicate that single hole-type carries with high density and low mobility dominate the transport properties of o-CuMnAs. Furthermore, the result of low-temperature heat capacity shows that the effective mass of carriers is much larger than those in typical topological semimetals. These results imply that the carriers in o-CuMnAs exhibit remarkably different features from those of Dirac fermions predicted in theory.

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Xiao Zhang, Shanshan Sun, Hechang Lei. 2017-12-09. Massive fermions with low mobility in antiferromagnet orthorhombic CuMnAs single crystals. https://doi.org/10.1103/physrevb.96.235105

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