J. Michael Kosterlitz
active c. 1943, Aberdeen, Scotland
British-American physicist, co-discoverer of the Kosterlitz–Thouless topological phase transition in two-dimensional systems.
Kosterlitz was Thouless's postdoc at Birmingham when the two developed the vortex theory of 1972–73. He reformulated phase transitions without 'mean fields' — using renormalization applied to topological defects. He has taught at Brown since 1982, working on thin-film superconductors and disordered systems.
Nobel-winning work
The KT theory (1973) explains that in two dimensions, long-range order is destroyed not by spin waves but by point defects — vortices. Below a critical temperature vortex–antivortex pairs stay 'bound' preserving quasi-long-range order; above it they dissociate freely. It is the most 'exotic' transition — no local order parameter — and opened topological thinking in materials.
Workplaces: Brown University, University of Birmingham
United Kingdom, United States