Professor Pengcheng Dai
Department of Physics and Astronomy
Rice University
Host: Gannon
Title: Magnetic order and spin excitations in two-dimensional honeycomb lattice van der Waals ferromagnetic CrI3
Abstract: We use neutron scattering to study magnetic order and spin excitations in honeycomb lattice van der Waals ferromagnet CrI3. We show that ferromagnetic phase transition is first order in nature, and controlled by spin-orbit coupling (SOC) induced magnetic anisotropy, instead of magnetic exchange coupling as in a conventional ferromagnet. We discuss the role of the next-nearest-neighbor Dzyaloshinskii-Moriya interaction and Kitaev’s interaction plays on the spin-wave spectra and the possible presence of topological spin excitations in CrI3.