- Person
- David Lee
- Lived
- b. 1931
- Field
- Low-temperature physics
- From
- American
The story
David Lee was born in 1931 in Rye, New York, the son of an electrical engineer and a schoolteacher who were the children of Jewish immigrants from England and Lithuania. After Harvard, Army service and a doctorate at Yale on liquid helium-3, he joined Cornell University in 1959 with the job of building a low-temperature laboratory from scratch.
Helium comes in two forms. Common helium-4 becomes a superfluid, a liquid with no internal friction, at about two degrees above absolute zero. Rare helium-3 obeys different quantum rules and cannot do the same in a simple way. Theory suggested that helium-3 atoms might pair up, as electrons do in a superconductor, and then become superfluid at a far lower temperature. Through the 1960s many groups searched without success, and some doubted it could happen.
Lee, his colleague Robert Richardson and graduate student Douglas Osheroff were in fact looking for a magnetic transition in solid helium-3, using a Pomeranchuk cell, which cools the helium by compressing it until part of it freezes. In November 1971 Osheroff noticed small kinks in the pressure recordings. The team took them seriously. Their first paper in 1972 attributed the effect to the solid, but further measurements that year showed it came from the liquid, which was passing through two new phase transitions. Helium-3 had become a superfluid, with more than one superfluid phase.
The discovery opened a new field. Superfluid helium-3 proved to be one of the richest quantum systems known, with direction-dependent properties and many kinds of vortices, and it has served as a model for unusual superconductors, neutron stars and even theories of the early universe. The Nobel committee said it showed that the quantum laws of the microscopic world can directly govern the behaviour of large bodies. Lee, Osheroff and Richardson shared the 1996 Nobel Prize in Physics.
Why it matters
Superfluid helium-3 became a laboratory for testing ideas about quantum matter, and the ultra-low-temperature techniques developed by groups like Lee’s now help cool sensitive experiments and superconducting quantum computers.
About David Lee
Cornell physicist who built the low-temperature laboratory where helium-3 was found to become a superfluid near absolute zero, opening a new window on quantum matter. Nobel Prize 1996.
Sources
- Press release: The Nobel Prize in Physics 1996 NobelPrize.org
- David M. Lee, Biographical NobelPrize.org
- David Lee (physicist) Wikipedia
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