Physicists in the United States have devised a new theory which could have revolutionary implications for the field of electrical engineering by bringing high-temperature superconductors a major step closer to reality.
The new theory seeks to explain the broad gamut of peculiar behaviour displayed by high-temperature superconductors, which has thus far frustrated efforts by engineers and scientists to convert them into a viable material for practical applications.
The property of superconductivity involves the flow of electrical current with almost zero resistance, and was first uncovered by scientists in metals which had been cooled to temperatures approaching absolute zero.
In recent decades scientists have discovered that certain metallic compounds, comprised of complex crystalline structures of copper, iron and other metals, are capable of superconductivity at temperatures as high as 150 degrees Kelvin (-123.15 degrees Celsius), making them far more amenable to practical usage.
Unfortunately, however, these materials also display a varied range of peculiar behaviours, referred to by physicists as “intertwined ordered phases,” which severely impedes their superconducting properties. These behaviours include electrons spontaneously falling into stripe-like formations, or failing to form symmetrical patterns around atoms.
J.C. Seamus Davis, the James Gilbert White Distinguished Professor in the Physical Sciences at Cornell and director of the Center for Emergent Superconductivity at Brookhaven National Laboratory, and Dung-hai Lee, professor of physics at the University of California-Berkeley as well as faculty scientist at Lawrence Berkeley National Laboratory, believe their new theory may account for these debilitating irregularities.
According to their theory, which has been published in the Proceedings of the National Academy of Sciences, both superconductivity and the strange behaviour displayed by superconducting materials at higher temperatures share a single underlying cause – the “antiferromagnetic” state which occurs when the magnetic moments of electrons are opposed.
This state is responsible for both the odd patterns of electrons which arise in high temperature superconductors, as well as the “Cooper pairs” of electrons that permits them to make their passage without resistance.
Their insight could provide scientists with the key to devising superconductors which are capable of functioning effectively at higher temperatures. If their theory proves correct, it means superconducting materials must be designed so that electrons are able to engage in antiferromagnetic interactions while also being free enough to form the Cooper pairs which negate resistance.
The ability to design superconductors capable of functioning at room temperature would have a revolutionary impact upon electrical engineering, permitting the creation of both generators and motors capable of transmission of power with minimal loss.