A team of researchers from the University of British Columbia, coordinated by Physics Assoc. Prof. Andrea Damascelli, has managed to develop a technique that controls the number of electrons from the surface of a high temperature superconductor. This procedure has been considered impossible for the last 20 years.
The team deposited potassium atoms on the surface of a piece of superconducting copper oxide. It is known that recently it has been discovered that not only copper-oxide materials can be made to be superconductors, but also the iron has this property. This control approach allows the scientists to manipulate the number of electrons on ultra-thin layers of material in a continuous matter.
Superconductivity occurs in copper-oxide materials at very low temperatures. High-temperature superconductors are a class of materials capable of conducting electricity with very low resistance in temperatures as high as -140 degrees Celsius (that’s considered “high” for superconducting abilities).
“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.
The study was carried out partially at the Advanced Light Source synchrotron from California. 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 Damascelli’s leadership.