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arXiv · 1910.13383

XFe4Ge2 (X = Y, Lu) and Mn3Pt: Filling-enforced magnetic topological metals

Di Wang·Feng Tang·Hoi Chun Po·Ashvin Vishwanath·Xiangang Wan
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Abstract

Magnetism, coupled with nontrivial band topology, can bring about many interesting and exotic phenomena, so that magnetic topological materials have attracted persistent research interest. However, compared with non-magnetic topological materials (TMs), the magnetic TMs are less studied, since their magnetic structures and topological phase transitions are usually complex and the first-principles predictions are usually sensitive on the effect of Coulomb interaction. In this work, we present a comprehensive investigation of XFe4Ge2 (X = Y, Lu) and Mn3Pt, and find these materials to be filling-enforced magnetic topological metals. Our first-principles calculations show that XFe4Ge2 (X = Y, Lu) host Dirac points near the Fermi level at high symmetry point S. These Dirac points are protected by PT symmetry (P and T are inversion and time-reversal transformations, respectively) and a 2-fold screw rotation symmetry. Moreover, through breaking PT symmetry, the Dirac points would split into Weyl nodes. Mn3Pt is found to host 4-fold degenerate band crossings in the whole high symmetry path of A-Z. We also utilize the GGA+U scheme to take into account the effect of Coulomb repulsion and find that the filling-enforced topological properties are naturally insensitive on U.

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Di Wang, Feng Tang, Hoi Chun Po, Ashvin Vishwanath, Xiangang Wan. 2019-10-29. XFe4Ge2 (X = Y, Lu) and Mn3Pt: Filling-enforced magnetic topological metals. https://doi.org/10.1103/physrevb.101.115122

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