Simon Fraser University

Herbut attracts attention of peer

Feb 21, 2002 , vol.23, no.4

By Carol Thorbes
Igor Herbut's insight into the Yin Yang behaviour of one of the most intriguing phenomenon in solid state physics is attracting his peers' attention.

The Simon Fraser University physicist's mathematical description of the behaviour of a new group of superconductors was posted on the American Physical Society's (APS) website ( on Jan. 14.
Since then, dozens of physicists, worldwide, have been poring over Herbut's theory, which was published in Physical Review Letters, APS's weekly letter, on Jan. 28.

Physical Review Letters is internationally recognized as the premier peer review journal for physicists. Its membership and readership are in the tens of thousands.

Herbut and his fellow researchers in solid state physics (physics of solids, liquids, glass) are locked in a race to unravel the mystery of what causes high temperature superconductors to behave in a very metaphysical way.

Superconductors, which operate at extremely low temperatures (approx. minus 260 Celsius), transmit electrical current without dissipation and at a much faster rate than conventional conductors, which function at room temperature.

High temperature super-conductors conduct many more electrons in a shorter space of time than conventional superconductors, and can do so at a higher temperature (minus 200 to minus 173 Celsius).

“High temperature super-conductors hold the promise of being more useful and flexible than their conventional counterparts in industry and research. Their superior electrical conductivity makes it possible to accomplish the work of 10 wires in a conventional superconductor with one wire,” explains Herbut, an assistant professor of physics.

Ultimately, high temperature superconductors could be as revolutionary to electronics and to the transmission of electrical power as fibre optics was to telecommunications.

Another advantage of high temperature superconductors is they don't require liquid helium like their conventional counterparts to be cooled to their extremely low critical temperatures.

Liquid helium is difficult to obtain and expensive. High temperature superconductors only require liquid nitrogen to reach their critical temperature. It's less costly and more easily obtained.

Two Swiss scientists won the Nobel prize 16 years ago when they discovered that some magnetic insulators may become super-conductors in extremely cool temperatures. No one has figured out what makes these insulators, which usually have a significant copper component, function as superconductors at higher temperatures.
By turning the problem around (i.e., asking what makes some superconductors become magnetic insulators rather than the other way around) Herbut has stumbled on high temperature superconductors' paradoxical nature.

“Through mathematical equations I was able to prove that materials that superconduct electricity at relatively high temperatures are magnetic insulators in their natural state,” explains Herbut. “When you subtract electrons you discover these superconductors are inherently unstable towards magnetic insulation.”

Herbut hopes a detailed analysis of high temperature superconductors' Yin Yang transformation will lead to clues on how to control the process.