Wallace Lecture

Transport, Magnetic and Optical Properties of Non-colinear Antiferromagnets

Qian Niu

Department of Physics
University of Texas

In a class of materials, such as Mn₃Ir and Mn₃Sn, magnetic moments lie in planes of kagome lattices, pointing away from each other by 120 degrees. The net spin moment vanishes, but one can still have large anomalous Hall effect, orbital magnetization, and magneto-optical Kerr effects. Spin-orbit coupling, aided by certain spatial symmetry breaking, plays the key role for allowing such ferromagnet-like phenomena to happen.