Quest for correct answer led Kosterlitz to new definition of ordered phase of matter - and Onsager Prize

Paper written in 1973 with colleague David Thouless was considered fairly controversial at the time

Physics professor J. Michael Kosterlitz received the 2000 Lars Onsager Prize of the American Physical Society at its March meeting in Minneapolis.

Kosterlitz received the prize along with his colleague, David Thouless of the University of Seattle, for recognition of their 1973 paper in which they came up with a new definition of an ordered phase of matter. The paper was written when they were at Birmingham University in England.

The recognition has come decades later, Kosterlitz said, because the paper "was fairly controversial when we did it and it took a while for it to be accepted." In addition, the Onsager prize was created only a few years ago and has been awarded annually since 1995. The prize, which consists of $15,000, is given to recognize outstanding research in theoretical statistical physics including the quantum fluids.

The theory of Kosterlitz and Thouless was controversial "because it disagreed with the accepted wisdom of the time," Kosterlitz said. "Dave Thouless and I just looked at the problem in an unusual point of view which allowed calculations to be done.... Basically we argued that the definition of a two-dimensional crystal should be modified. What was important about a crystal was not the order of the atoms, but the fact that the crystal solid would have some rigidity."

Kosterlitz shares the passion for analytical results for which Onsager is known.

"I was always attracted toward physics from a rather early age," about 12 or 13, "because things like physics and mathematics seemed to be about the only subjects where there were correct answers. The answers in other subjects seemed to be dependent on the teacher; the only answer that counted was the one that the teacher counted as correct. I could never understand why the teacher's opinion was more correct than mine," Kosterlitz said.

The quest for the correct answer led him to propose an unheard-of theory that scientists today call "remarkable."

"At the time, I'd just done my graduate work in elementary particle physics, and I was looking for something else. I was tired of doing endless complicated calculations for no return, and I changed my field to condensed matter physics. I was very ignorant of the so-called correct way to do things. So these sorts of ideas didn't seem particularly strange to me. It just felt right."

The prize is named for Onsager, a Norwegian-born physicist who taught at Brown for five years starting about 1928. Onsager received the Nobel Prize for chemistry in 1968. Brown awarded Onsager an honorary degree in 1962.