Emergence of 2D high-temperature nodal-line half-metal in monolayer AgN

• Published in: Physical chemistry chemical physics : PCCP Vol. 22; no. 46; pp. 2724 - 273
• Main Authors: Li, Xin-Yang, Zhang, Meng-Han, Ren, Miao-Juan, Zhang, Chang-Wen
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 07.12.2020
• Subjects: Electrons; Fermions; First principles; High temperature; Magnetic properties; Structural analysis
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/d0cp04961a

Nodal-line half-metals (NLHMs) are highly desirable for future spintronic devices due to their exotic quantum properties. However, the experimental realization in spin-polarized materials is nontrivial to date. Herein we perform first-principles calculations to demonstrate a 2D honeycomb, AgN, as a promising candidate of NLHMs, which is thermodynamically and dynamically stable. Band structure analysis reveals that two concentric NLs coexist centered at a Γ point near E F , accompanied by the electron and hole pockets that touch each other linearly with single-spin components. Inclusion of SOC can enrich the electronic structures of AgN, sensitive to the protection of mirror reflection symmetry: the NLHM survives if the spin is perpendicular to the M z mirror plane, while it tunes into Wyle nodal-points by rotating spins from the out-of-plane to the in-plane direction. The characteristics of HM and NL can be well maintained on semiconducting h-BN and is immune to mechanical strains. These tunable magnetic properties render 2D AgN suitable for exotic quantum transports in nodal fermions as well as related spintronic devices. Nodal-line half-metals (NLHMs) are highly desirable for future spintronic devices due to their exotic quantum properties.