Two with Cornell ties share 2016 Nobel Prize in physics

By: Tom Fleischman,  Cornell Chronicle
Mon, 10/03/2016

More than 40 years ago, David J. Thouless, Ph.D. ’58, and J. Michael Kosterlitz, a postdoctoral researcher at Cornell 1973-74, successfully challenged conventional wisdom that superfluidity or superconductivity could not occur in infinite two-dimensional systems.

They also explained “phase transition” – the mechanism that makes superconductivity disappear at higher temperatures. In fact, that mechanism is known as the KT (Kosterlitz-Thouless) transition.

Due in part to that pioneering work from the early ’70s, scientists are now on the hunt for new and exotic phases of matter, with applications in materials science and electronics.

For their revolutionary research, Thouless and Kosterlitz – along with Princeton University physics professor F. Duncan M. Haldane – have been awarded the 2016 Nobel Prize in physics, the Royal Swedish Academy of Sciences announced Oct. 4 in Stockholm.

The Royal Swedish Academy announced the prize of approximately $930,000 is being split two ways: Thouless, emeritus physics professor at the University of Washington, will receive half of the prize because of his “crucial contributions” on multiple fronts. Kosterlitz, physics professor at Brown University, and Haldane will split the remainder.

“This year’s laureates opened the door on an unknown world where matter can assume strange states,” the Royal Swedish Academy said in a statement announcing the winners. “They have used advanced mathematical methods to study unusual phases, or states, of matter, such as superconductors, superfluids or thin magnetic films.

“The three laureates’ use of topological concepts in physics was decisive for their discoveries,” the statement said. Topology is the mathematical study of the properties that are preserved through deformation, twisting and stretching (but not tearing) of an object.

John Reppy, the John L. Wetherill Professor Emeritus of Physics, knows both Thouless and Kosterlitz. He said Thouless was identified early on as having great promise.

“He was a Ph.D. student of Hans Bethe,” Reppy said, referring to the 1967 Nobel Prize winner, best known for his work on the Manhattan Project, who taught at Cornell from 1935 until his retirement in 1975. “Bethe thought very highly of Thouless, mainly because, when he came to Cornell as a novice graduate student, he asked Bethe for a thesis topic. Bethe gave him one, and Thouless disappeared.

“And after some time, he returned and had completed the thesis topic and was ready to graduate,” Reppy said. “[Thouless] was really quite exceptional.”

Reppy’s interactions with Kosterlitz most often came on the side of a large rock, as both are avid climbers. They first met in Birmingham in the early 1970s, when Reppy was on sabbatical in Manchester, England, and went to Birmingham to give a talk. They later met at Stanage Edge, a well-known climbing area in England.

“He’s not only a top-notch physicist, but a world-class climber,” Reppy said.

Over the past decade, the Swedish Academy noted, the study of topological phases – not only in thin layers but also in three-dimensional materials – has advanced front-line research in condensed-matter physics. It is seen as pushing science toward new generations of electronics and superconductors, as well as quantum computing.

“Current research is revealing the secrets of matter in the exotic worlds discovered by this year’s Nobel laureates,” the academy said in its statement.

“[The KT-transition] is very simple,” Reppy said, “therefore it’s going to be at the basis of a whole raft of two-dimensional physics problems.”

Thouless, 82, was born in Bearsden, Scotland, and received his undergraduate degree from the University of Cambridge in 1952. Kosterlitz was born in 1942 in Aberdeen, Scotland; he received his undergraduate degree from Cambridge in 1962, and his doctorate from Oxford in 1969.

Thouless brings to 46 the number of Nobel Prize winners who are affiliated with Cornell as alumni or current or former faculty members.

This article also appeared in the Cornell Chronicle.