Vinay Ambegaokar, the Goldwin Smith Professor of Physics Emeritus, has been awarded the 2015 John Bardeen Prize in recognition of his theoretical research, which has substantially advanced understanding of unique and fundamental features of superconductivity. The late Bardeen is the only person to be awarded two Nobel Prizes in physics.
Nobel laureate Anthony J. Leggett, chair of the Bardeen Prize Committee, noted that Ambegaokar was recognized for his contributions to the statics, dynamics and kinetics of Josephson junctions and nanowires, which are devices that can carry a certain amount of electrical current without any resistance. They are extremely sensitive detectors of magnetic fields and are used in applications as diverse as brain research, astronomy and cosmology.
“Professor Ambegaokar developed theoretical methods for calculating the limiting amount of current that such systems can carry while still maintaining a zero-resistance state,” said Jeevak Parpia, Cornell professor and chair of physics. “He and his colleagues were the first to correctly predict their temperature dependence and to understand the dominant mechanisms that limit the amount of zero-resistance current that a nanowire can carry.”
In June 1963, Ambegaokar, with his student Alexis Baratoff, published the first calculation of the temperature dependence of the Josephson current, named after Welsh theoretical physicist Brian Josephson. Ambegaokar originally had set out to disprove Josephson’s calculations – after learning of Bardeen’s skepticism over the same – but Ambegaokar’s calculations agreed with Josephson’s. Prior to publishing his findings, Ambegaokar corresponded with Bardeen, who called his calculation elegant but incorrect. The Josephson current was experimentally detected that summer, and Bardeen conceded.
Low temperature and condensed matter physics are Ambegaokar’s main areas of interest. He has produced seminal theoretical work in the areas of superconductivity and superfluidity, or frictionless matter flow in liquid helium without resistance. His current work focuses on aspects of disordered metallic conductors, quantum information and its loss through decoherence, and mathematical ways of describing these phenomena.
Ambegaokar received a bachelor's and master's degrees in 1956 from the mechanical engineering honors program at the Massachusetts Institute of Technology, and a doctorate in 1960 in theoretical physics from the Carnegie Institute of Technology. His many honors include the Medal of the University of Helsinki and the Medal of the Collège de France. He has been a fellow of the American Physical Society since 1979.
The Bardeen Prize is sponsored by the Department of Physics at the University of Illinois at Urbana-Champaign and by the Friends of Bardeen. The prize is presented triennially for theoretical work that has provided significant insights on the nature of superconductivity and has led to verifiable predictions. It will be presented to Ambegaokar Aug. 24 during the 11th International Conference on Materials and Mechanisms of Superconductivity in Geneva, Switzerland.