CANCELLED until later notice: Prof. Liuyan Zhao, University of Michigan,Ann Arbor, Complex magnetic excitations in a honeycomb ferromagnet CrI3

Date: Mon. March 30th, 2020, 12:45 pm-1:45 pm
Location: Rockefeller 221 (Les Foldy Room)
Website: https://lsa.umich.edu/physics/people/faculty/lyzhao.html

Complex magnetic excitations in a honeycomb ferromagnet CrI3

Liuyan Zhao, Department of Physics, University of Michigan, Ann Arbor

Two-dimensional (2D) honeycomb ferromagnetic monolayers are predicted to host massless Dirac magnons because of the two equivalent magnetic sites per unit cell of the honeycomb lattice, mimicking Dirac electrons in graphene. More interestingly, the introduction of the next-nearest-neighbor Dzyaloshinskii-Moriya interaction breaks the sublattice equivalency and suggests the emergence of topological magnons in these honeycomb ferromagnets. Recenly, CrI3, a honeycomb ferromagnet, has attracked tremendous attention because of the long-range 2D ferromagnetic order in its monolayer, the interlayer antiferromagnetic order in its few layers, and the ferromagnetic order in its bulk. Extensive research efforts have been made to understand the thickness-dependent magnetism and to explore device applications of the thin films. However, nearly all these efforts have been focused in the static orders, i.e., magnetic ground state, leaving the magnon dynamics as an open topic to be addressed. In this talk, I will present polarization-resolved Raman spectroscopy studies on magnetic excitations in a honeycomb ferromagnet CrI3, as a function of temperature, layer number, and external magnetic field

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Host: Xuan Gao