学术报告：Topological Order and Defects, and Phase Transitions in Two Dimensions
报告人：J. M. Kosterlitz
John Michael Kosterlitz
2016 Nobel Laureate in Physics (with David Thouless and Duncan Haldane)
Harrison E Farnsworth Professor of PhysicsBrown University
Born in Aberdeen, Scotland, in 1943, Kosterlitz earned his Ph.D. from Oxford University in 1969. After an appointment as a postdoctoral researcher at Torino University in Italy, he became a research fellow at Birmingham University in 1970 before coming to Brown in 1982. He is a fellow of the American Physical Society and received the Maxwell Medal from the U.K. Institute of Physics in 1980. In 2000 he was awarded the Lars Onsager Prize by the American Physical Society. In 2016, he was awarded the Nobel Prize in Physics with David Thouless and Duncan Haldane. He was inducted into the American Academy of Arts and Sciences as a fellow in 2007, and was elected a member of the US National Academy of Sciences in 2017.
Man's understanding of matter, the distinct phases of it, started from water, or vapor, water, ice. The vapor-water transition, the phenomenon of condensation, was first understood by van der Waals (Nobel Prize in Physics 1910). But the melting transition of solid has eluded us, still in 3D. We made the breakthrough in understanding 2D melting and phase transitions that got us the Nobel Prize. In 1D, there is no solid to melt which was understood by Lev Landau (Nobel Prize in Physics 1962) long time ago. Landau's ideas of characterizing matter based on broken symmetries and long-range order gave us the tools to understand many things in nature, magnets, in particular. But Laudau's idea was too strict, it turns out long-range order was not the most essential property of being a solid, it's the shear rigidity that makes solid a solid. In two-dimensions, Thouless and I proved that you can have a solid-liquid transition based on the unbinding of topological defects. It turns out this idea has broad applications to the understanding of many materials, superfluid helium films, magnets, liquid crystals, and quantum spin chains (Haldane, co-Nobel laureate).