Magnetic interactions and excitations in van der Waals materials and topological rare-earth magnets: ab initio calculations and modelings
Speaker: Liqin Ke of the Division of Materials Science and Engineering at Ames Laboratory
When: Friday, April 8, 2022 , 3:30 – 4:30 pm.
Abstract
Understanding, developing, and improving magnetic materials are of great interest for fundamental sciences and practical applications. We discuss ab initio calculations and analytical modelings of magnetic interactions and excitations using several example systems, including magnetic 2D van der Waals materials, permanent magnets, and the Kagome-lattice topological rare-earth magnets. We calculate spin excitations in CrI3 and directly compare results to inelastic neutron scattering measurements. We discuss the effects of electron correlations and potential magnon gap opening mechanisms related to the topological nature of magnetic interaction. We use analytical modeling to illustrate the mechanism and evolution of magnetocrystalline anisotropy in two very different systems; more specifically, 1) Band-filling effect on magnetic anisotropy in a 3d-electron system, 2) Evolution of anisotropy with constituent 4f-elements in rare-earth intermetallics RMn6Sn6.
> [1] L. Ke, M. I. Katsnelson. npj Computational Materials, 7(4):1-8 (2021)
> [2] Y. Lee /et al/. arXiv:2201.11265 (2022)
> [3] L. Ke, M. van Schilfgaarde, PRB 92 (1), 014423 (2015) https://nam11.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdx.doi.org%2F10.1103%2FPhysRevB.92.014423&data=04%7C01%7Cnghimire%40gmu.edu%7C5598b0d810f44cad7e7308da172772a6%7C9e857255df574c47a0c00546460380cb%7C0%7C0%7C637847755432335707%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=CRJR8BWCIUU5w%2B%2F50X4evAFL1kjxaeEJFb36XrTAw2o%3D&reserved=0
Bio
Liqin Ke is a research Scientist (PI) in the Division of Materials Science and Engineering at Ames Laboratory. He earned his Ph.D.~ from Arizona State University in 2009 for the ab initio studies of electronic transport in nanosystems and spin excitations. He joined Ames Lab in 2010 as a postdoctoral research associate and has been working on various projects with a focus on electronic structure and magnetism. He was a recipient of the DOE Early Career award. Currently, his research interests include:1) Electronic and magnetic properties of magnetic 2D van der Waals materials and topological magnets.2) Development of efficient ab initio methods to compute and analyze intrinsic magnetic properties, such as magnetocrystalline anisotropy, exchanges coupling, and dynamical spin susceptibility.3) Micromagnetic modeling of extrinsic magnetic properties and the growth mechanism of magnetic Skyrmions.4) Analytical modeling of spin-orbit-coupling relevant phenomena.
Meeting Information:
https://gmu.zoom.us/j/93426209769?pwd=TjNmaWpvMlYxRzZGUkNzeHdPV2g3QT09