Date(s) - 19/04/2018
1:30 pm - 2:30 pm
Title: Developmentand Validation of New Techniques for Nuclear Medicine
Speaker: Dr. Solomon Owerre
Institute: Peremeter Instiute
Description: Weyl nodes have been experimentally realized in photonic,
electronic, and phononic crystals. However, magnonic Weyl nodes are yet to be seen experimentally. In this talk, I will show a recent proposal of realistic Weyl magnon nodes in noncoplanar stacked frustrated kagome antiferromagnets, which are naturally available in various real materials. The Weyl magnon nodes in this system occur at the lowest excitation, which is synonymous with electronic Weyl nodes near the Fermi energy, and they possess a topological thermal Hall effect, and can be experimentally observed at low temperatures due to the population effect of bosonic quasiparticles.In stark contrast to other magnetic Weyl systems, the current Weyl nodes do not rely on time-reversal symmetry breaking by the magnetic order. Rather, they result from explicit macroscopically broken time reversal symmetry by the scalar spin chirality of noncoplanar spin textures, and can be generalized to chiral spin liquid states. Moreover, the scalar spin chirality gives a real space Berry curvature which is not available in previously studied magnetic Weyl systems. They also possess a Fermi (magnon) arc surface states connecting projected Weyl magnon nodes on the surface Brillouin zone.