It’s been 40 years since the first demonstration of high-temperature superconductivity. A new article published in Nature written by UC Davis physicists Inna Vishik and Warren Pickett takes a retrospective look at “this strange state of matter.”
Superconductors are materials that conduct electricity with zero resistance, meaning that they lose no energy to heating. Superconductivity is primarily a low-temperature phenomenon, the state existing well below room temperature, but in 1986, Georg Bednorz and Alexander Müller reported the discovery of superconductivity at -238.15 degrees Celsius, about 50% higher than the previous record.
“Bednorz and Müller made their discovery in a type of copper-oxide compound called a cuprate,” write Vishik and Pickett, both of the Department of Physics and Astronomy at the College of Letters and Science at UC Davis. “These materials ushered in the era of high-temperature superconductivity and continue to confound scientists to this day.”
Vishik and Pickett outline the initial discovery of superconductivity in 1911 and trace the steps Bednorz and Müller took to progress that research with cuprates. Much about these materials, though, remains a mystery.
“The mechanism of cuprate superconductivity remains disputed, in part because cuprates are unconventional materials in many ways,” Vishik and Pickett write. “First, the interactions between every electron in the material cannot be treated in an average manner, making them strongly correlated electron materials. This makes the cuprates’ properties difficult to predict. Second, the best pre-1986 superconductors had 3D cubic crystal structures, whereas cuprates are made from 2D sheets of copper and oxygen atoms, arranged into stacks.”
Vishik and Pickett note that following that advent of Bednorz’s and Müller’s discovery, scientists began envisioning a future powered by high-temperature superconductivity, a future with magnetic-levitation trains and lossless power transmission lines.
“This has yet to be realized, but a lag is not unprecedented,” they write. “Existing technologies that use conventional superconducting materials came to fruition decades after the initial discoveries. The work that began in 1986 is still rich with intriguingly unexplained physics and potential breakthroughs.”
You can read Vishik’s and Pickett’s full “in retrospect” article here.
YOU MAY ALSO LIKE THESE STORIES
A New Road Map to Room Temperature Superconductors
The discovery of room-temperature superconductors would open a huge range of applications and new technologies. There are no physical laws that rule out such materials, according to a recent perspectives article by a group of scientists including Warren Pickett, Distinguished Professor Emeritus of physics and astronomy at UC Davis.
Inna Vishik on the Hype and Reality of Superconductivity
During a Dean’s Faculty Fellow Public Talk, Inna Vishik guided attendees through “Superconductivity: The Hype and the Reality.” The lecture took a sobering look at the field while also providing insight into the latest research developments from Vishik and her UC Davis colleagues.