- By:
- Chen, Lebing; Chung, Jae; Chen, Tong; Duan, Chunruo; Schneidewind, Astrid; Radelytskyi, Igor; Voneshen, David; Ewings, Russell; Stone, Matthew B; Kolesnikov, Alexander I; Winn, Barry L; Chi, Songxue ; Mole, R; Yu, D H; Gao, Bin; Dai, Pengcheng
- Journal Name:
- Physical Review B
- Page Number:
- 134418
- Volume:
- 101
- Issue Number:
- 13
- Publication Date:
- November 9, 2023
- View DOI Listing:
- https://doi.org/10.1103/PhysRevB.101.134418
Abstract
We use neutron scattering to show that ferromagnetic (FM) phase transition in the two-dimensional (2D) honeycomb lattice CrI3 is a weakly first order transition and controlled by spin-orbit coupling (SOC) induced magnetic anisotropy, instead of magnetic exchange coupling as in a conventional ferromagnet. With increasing temperature, the magnitude of magnetic anisotropy, seen as a spin gap at the Brillouin zone center, decreases in a power law fashion and vanishes at TC, while the in-plane and c-axis spin-wave stiffnesses associated with magnetic exchange couplings remain robust at TC. We also compare parameter regimes where spin waves in CrI3 can be described by a Heisenberg Hamiltonian with Dzyaloshinskii-Moriya interaction or a Heisenberg-Kitaev Hamiltonian. These results suggest that the SOC induced magnetic anisotropy plays a dominant role in stabilizing the FM order in single layer 2D van der Waals ferromagnets.
