'Impossible' technique to study and develop superconductors
Date: Monday, June 23, 2008 @ 23:14:57 GMT
A team of University of British Columbia researchers has developed a
technique that controls the number of electrons on the surface of
high-temperature superconductors, a procedure considered impossible for
the past two decades.
Led by Physics Assoc. Prof.
Andrea Damascelli, the team deposited potassium atoms onto the surface
of a piece of superconducting copper oxide. The approach allows the
scientists to continuously manipulate the number of electrons on
ultra-thin layers of material.
The details are published this week in the prestigious journal Nature Physics.
Superconductivity – the
phenomenon of conducting electricity with no resistance – occurs in
some materials at very low temperatures. High-temperature
superconductors are a class of materials capable of conducting
electricity with little or no resistance in temperatures as high as
-140 degrees Celsius.
"The development of future electronics, such as quantum computer
chips, hinges on extremely thin layers of material," says Damascelli,
Canada Research Chair in the Electronic Structure of Solids.
"Extremely thin layers and surfaces of superconducting materials
take on very different properties from the rest of the material.
Electrons have been observed to re-arrange, making it impossible for
scientists to study," says Damascelli. "It's become clear in recent
years that this phenomenon is both the challenge and key to making
great strides in superconductor research.
"The new technique opens the
door to systematic studies not just of high-temperature
superconductors, but many other materials where surfaces and interfaces
control the physical properties," says Damascelli. "The control of
surfaces and interfaces plays a vital role in the development of
applications such as fuel cells and lossless power lines, and may lead
to new materials altogether."
The superconductors Damascelli's team experimented on are the
purest samples currently available and were produced at UBC by
physicists Doug Bonn, Ruixing Liang and Walter Hardy.
Part of the study was carried out at the Advanced Light Source
synchrotron in California. In the future, the design and study of novel
complex materials for next-generation technologies will be carried out
at the Quantum Materials Spectroscopy Center currently under
construction at the Canadian Light Source in Saskatoon under
Source: University of British Columbia