Leggett, Anthony James (1938– )

British-born US physicist who was awarded the Nobel Prize for Physics in 2003 for his role in the development of the theory of superfluids. He shared the award with Russian-born US theoretical physicist Alexei A Abrikosov and Russian physicist Vitalii L Ginzburg.

The viscosity of liquid helium disappears as the material is cooled to close to absolute zero. This phenomenon is known as superfluidity. In the case of the superfluid helium isotope, 3He, the atoms pair up in a matter similar to electrons in a metallic superconductor. Leggett developed a theory in the 1970s of how individual helium atoms interact to form this ordered structure. Understanding how superfluids work provides invaluable insights into how matter behaves in its lowest ordered fundamental state.

Leggett was born in London, England, and received his doctorate in theoretical physics from Magdalen College at the University of Oxford, England, in 1964. He joined the University of Sussex in 1967 as a lecturer and was professor of physics there 1978–83. Leggett then joined the faculty of the University of Illinois at Urbana-Champaign, Urbana, Illinois, in 1983. He was elected a member of the US National Academy of Sciences in 2000 and became a foreign member of the Royal Society, London, in 2001. Leggett shared the Wolf Prize for Physics with US physicist Bertrand Halperin in 2003.