Two-dimensional half-metallicity and fully spin-polarized topological fermions in monolayer EuOBr

Chenyao Li; Minghang Li; Yefeng Li; Tingli He; Ying Liu; Xiaoming Zhang; Xuefang Dai; Guodong Liu

doi:10.1088/1361-648X/acc8b2

Two-dimensional half-metallicity and fully spin-polarized topological fermions in monolayer EuOBr

J Phys Condens Matter. 2023 Apr 6;35(26). doi: 10.1088/1361-648X/acc8b2.

Authors

Chenyao Li^{1

2}, Minghang Li^{1

2}, Yefeng Li^{1

2}, Tingli He^{1

2}, Ying Liu^{1

2}, Xiaoming Zhang^{1

2}, Xuefang Dai^{1

2}, Guodong Liu^{1

2}

Affiliations

¹ State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300130, People's Republic of China.
² School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130, People's Republic of China.

PMID: 36990099
DOI: 10.1088/1361-648X/acc8b2

Abstract

Two-dimensional (2D) half-metal and topological states have been the current research focus in condensed matter physics. Herein, we report a novel 2D material named EuOBr monolayer, which can simultaneously show 2D half-metal and topological fermions. This material shows a metallic state in the spin-up channel but a large insulating gap of 4.38 eV in the spin-down channel. In the conducting spin channel, the EuOBr monolayer shows the coexistence of Weyl points and nodal-lines near the Fermi level. These nodal-lines are classified by type-I, hybrid, closed, and open nodal-lines. The symmetry analysis suggests these nodal-lines are protected by the mirror symmetry, which cannot be broken even spin-orbit coupling is included because the ground magnetization direction in the material is out-of-plane [001]. The topological fermions in the EuOBr monolayer are fully spin-polarized, which can be meaningful for future applications in topological spintronic nano-devices.

Keywords: 2D material; ferromagnetic; fully spin-polarized; half-metals; nodal line; topological magnetism.