2020/06/30 by Joren Vanherck, Cihan Bacaksiz, Bart Sorée +2
Materials Science · Physics and Astronomy · #2D Materials and Applications #Ab initio #Curie temperature #Excitation #Ferromagnetism #Heisenberg model #Iron-based superconductors research #Magnetic field #Magnetization #Quantum #Topological Materials and Phenomena #cond-mat.mes-hall #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1063/5.0015619
published as Appl. Phys. Lett. 117, 052401 (2020) · 14 pages, 5 figures. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 117, 052401 (2020) and may be found at https://doi.org/10.1063/5.0015619
openalex publication_date 2020/08/03 · arxiv created 2020/08/10 · openalex created_date 2020/08/10 · arxiv updated 2020/08/11 · openalex updated_date 2026/08/05
Recent years have seen a tremendous rise of two-dimensional (2D) magnetic materials, several of which were verified experimentally. However, most of the theoretical predictions to date rely on ab initio methods, at zero temperature and fluctuation-free, while one certainly expects detrimental quantum fluctuations at finite temperatures. Here, we present the solution of the quantum Heisenberg model for honeycomb/hexagonal lattices with anisotropic exchange interaction up to third nearest neighbors and in an applied field in arbitrary direction, which answers the question whether long-range magnetization can indeed survive in the ultrathin limit of materials, up to which temperature, and what the characteristic excitation (magnon) frequencies are, all essential to envisaged applications of magnetic 2D materials. We find that long-range magnetic order persists at finite temperature for materials with overall easy-axis anisotropy. We validate the calculations on the examples of monolayers CrI3, CrBr3, and MnSe2. Moreover, we provide an easy-to-use tool to calculate Curie temperatures of new 2D computational materials.