Two-dimensional antiferromagnetic nodal-line semimetal and spin Hall effect in MnC4

• Published in: Journal of physics. Condensed matter Vol. 36; no. 15
• Main Authors: Fernandez, H, Gonzalez-Hernandez, R, Paez, J, Hoat, D M, Takeuchi Tan, N, Guerrero-Sanchez, J, Perez-Tijerina, E G
• Format: Journal Article
• Language: English
• Published: IOP Publishing 17.04.2024
• Subjects: antiferromagnetic spintronics; Dirac-nodal line; spin Hall effect; topological antiferromagnet
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/1361-648X/ad1a7a

Nodal-line semimetals, characterized by Dirac-like crossings along one dimensional k-space lines, represent a unique class of topological materials. In this study, we investigate the intriguing properties of room-temperature antiferromagnetic MnC4 and its nodal-line features both with and without spin-orbit coupling (SOC). In the absence of SOC, we identify a doubly degenerate Dirac-nodal line, robustly protected by a combination of time-reversal, mirror, and partial-translation symmetries. Remarkably, this nodal line withstands various external perturbations, including isotropic and anisotropic strain, and torsional deformations, due to the ionic-like bonding between Mn atoms and C clusters. With the inclusion of SOC, we observe a distinctive quasi-Dirac-nodal line that emerges due to the interplay between antiferromagnetism and SOC-induced spin-rotation symmetry breaking. Finally, we observed a robust spin Hall conductivity that aligns with the energy range where the quasi-nodal line appears. This study presents a compelling example of a robust symmetry-protected Dirac-nodal line antiferromagnetic monolayer, which has potential for applications in next-generation spintronic devices.&#xD.