Year: 2020
Type: article
Abstract: The tetragonal ferrimagnetic ${\mathrm{Mn}}_{3}\mathrm{Ga}$ exhibits a wide range of intriguing magnetic properties. Here, we report the emergence of topologically nontrivial nodal lines in the absence of spin-orbit coupling (SOC) which are protected by both mirror and ${C}_{4z}$-rotational symmetries. In the presence of SOC, we demonstrate that the doubly degenerate nontrivial crossing points evolve into ${C}_{4z}$-protected Weyl nodes with chiral charge of $\ifmmode\pm\else\textpm\fi{}2$. Furthermore, we have considered the experimentally reported noncollinear ferrimagnetic structure where the magnetic moment of the ${\mathrm{Mn}}_{I}$ atom (on the Mn-Ga plane) is tilted by an angle $\ensuremath{\theta}$ with respect to the crystallographic $c$ axis. The evolution of the Weyl nodes with $\ensuremath{\theta}$ reveals that the double Weyl nodes split into a pair of charge-1 Weyl nodes whose separation can be tuned by the magnetic orientation in the noncollinear ferrimagnetic structure.
Language: Latvian
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3025624173