Electron-level properties of superconductors have been observed during changes, utilizing light pulses delivered through ultra-short bursts.
This new measurement is one of the most detailed images of the process ever recorded. Development of a new technique for measuring changes over an extremely short period of time is being compared to the invention of high-speed movie recording by Eadweard Muybridge.
University of British Columbia (UBC) researchers teamed with investigators from the Università Cattolica del Sacro Cuore in an effort to study the atomic behavior of superconductors. The team wanted to know if certain properties of superconductors developed instantly or over a period of time.
"The solution we devised is based on the use of ultra-fast light pulses, lasting 10 femtoseconds or 10 million billionths of a second," Claudio Giannetti from the Università Cattolica del Sacro Cuore in Italy said.
Muybridge was an English photographer born in 1830. He developed high-speed photography in an effort to settle a disagreement over whether or not horses lifted all four hooves in the air while running. He set up 12 cameras to take a series of photographs of horses, over a short period of time, in order to record action too fast to see with the human eye.
These new observations relied on a similar technique using short pulses of light to create a series of readings taken in a copper oxide superconductor.
Analysis shows that, however short, changes in electrons do take place over a given amount of time. These particles, including magnetic fields and the spin of their neighbors, interact with one another. The term "spin" does not refer to a physical movement but rather to a property of subatomic particles that can interact with matter in much the same way as a magnetic field.
This process is far too fast to be observed using traditional methods, and this is the first time that such changes have been seen in superconducting materials. Analysis of the data could be used to learn more about the mechanisms driving superconductivity in high-temperature conditions.
Superconductors are able to float in the air, making them a prime technology for magnet levitation (maglev) trains, among other applications. However, laboratory prototypes for such devices can only operate at temperatures just above absolute zero, which would make full-scale systems economically unfeasible. Even so-called high-temperature superconductors, such as those based on copper oxide, still need to be cooled to more than 200 degrees Fahrenheit below zero, far colder than dry ice.
Development of the new technique to analyze superconductors and analysis of the processes within the materials was detailed in the journal Nature Physics.
Photo: Trevor Prentice | Flickr
