Prof. Qian Niu: Large anomalous Hall and magneto-optical effects in noncolinear antiferromagnets (2016/01/07) |
| ( 2016-01-01 ) |
Title | Large anomalous Hall and magneto-optical effects in noncolinear antiferromagnets | Speaker | Prof. Qian Niu University of Texas at Austin, USA & Peking University |  | Time | 9：45am, January 7, 2016 | Place | Exhibition Hall, HFNL | | Brief Bio of the Speaker | Professor Qian Niu obtained a B.S. from Peking University in 1981. He went to the University of Washington for graduate studies, and received his Ph.D. in physics in 1985. Now he is a Trull Centennial Professor of Physics at the University of Texas at Austin, and an Adjunct Chair Professor at the International Center for Quantum Materials in Peking University. He has worked on the theories on quantum Hall effects, quasicrystals, ultracold atoms, spin transport, and graphene materials, with an emphasis on topological and geometric phase effects in quantum transport. He has published more than 220 peer reviewed papers, including 72 in Physical Review Letters, and has over 12000 citations (with an H index of 61). | Abstract | As established in the very early work of Edwin Hall, ferromagnetic conductors have an anomalous Hall conductivity contribution that cannot be attributed to Lorentz forces and therefore survives in the absence of a magnetic field. These anomalous Hall conductivities are normally assumed to be proportional to magnetization. We use symmetry arguments and first-principles electronic structure calculations to counter this assumption and to predict that Mn3Ir, a high-temperature antiferromagnet that is commonly employed in spin-valve devices, has a large anomalous Hall conductivity. Follow up work also show large magneto-optical Kerr effect in such systems. |
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