Seminar: Neutron Scattering and Thermal Transport Studies of Novel Magnetic Excitations in Low-Dimensional Magnets
Xianglin Ke(柯祥林)
Department of Physics and Astronomy,
Michigan State University
Time:15:30-17:00, Tuesday, June 27th, 2023
Abstract
Low-dimensional quantum magnetism has been one of actively pursued research topics in the past decades. After a brief overview of the research program, I will present our recent neutron scattering and thermal transport studies of magnetic excitations in two low-dimensional magnets. The first one is a 2D insulating van der Waals ferromagnet VI3. This material exhibits an anomalous thermal Hall effect with large thermal Hall signal over a wide temperature region. The observed thermal Hall effect is of dual nature, dominated by topological magnons hosted by the ferromagnetic honeycomb lattice at higher temperatures while being driven by magnon polarons via magnon-phonon coupling at lower temperatures. The second example I will present is a unique quasi-1D system, Cu2(OH)3Br, which consists of weakly-coupled, ferromagnetic and antiferromagnetic alternating chains. I will show that this system exhibits a coexistence of two different magnetic quasiparticles, magnons arising from ferromagnetic chains and spinons from antiferromagnetic chains. Furthermore, these two magnetic quasiparticles interact via weak interchain interactions.
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