Researchers at the University of British Columbia and Université de Sherbrooke have discovered that electrons are compelled to move in a preferred direction during the so-called 'pseudogap' phase of superconductors, revealing an underlying directive force that may also cause superconductivity.
The study, carried out at the Université de Sherbrooke in Quebec, was led by Canadian Institute for Advanced Research Quantum Materials Director Louis Taillefer, and took advantage of oxide crystals grown by UBC researchers led by Professor Douglas Bonn.
The findings were published in the January 28 issue of Nature.
Shedding light on this mysterious phase removes the main obstacle towards understanding why high-temperature superconductivity works, and takes us closer to a potential transformation of many technologies.
“Dozens of explanations for high-temperature superconductivity have been put forward over the years, but now the number of possible theories has been reduced to just a few – and we have a hunch which one of those is correct,” says Taillefer. “That means we can really start thinking about how to raise the maximum temperature at which superconductivity works – this discovery is a major step toward determining whether room-temperature superconductors might be possible.”
Superconducting materials have a number of fascinating and potentially highly useful properties, including the power to conduct electricity without resistance and the capacity to create powerful magnetic fields. Superconductors exhibit a “coherent” form of electricity, much as a laser exhibits a coherent form of light. These properties hold enormous technological implications – for power transmission, levitating high-speed trains, magnetic medical imaging, wireless communications and quantum computing.
"Our research has always had a major component devoted to growing crystals of yttrium barium copper oxide with the greatest possible attention to purity," says Bonn, Head of the Department of Physics and Astronomy at UBC and a member of the University's Advanced Materials and Process Engineering Laboratory.
"The samples coming from this group are recognized worldwide as the cleanest crystals anyone knows how to make, and this level of perfection enables the unique experiments being carried out by our collaborators."
The UBC team of collaborators on the study also included Professor Walter Hardy and materials scientist Ruixing Liang, both also with Physics and Astronomy.
“Research talent is broadly distributed among many institutions in this country," adds Taillefer. "CIFAR’s research model overcomes these geographic barriers and also gives us the time to take on complex, long-term research. Our discovery proves that Canada can be a global leader in some of the most exciting and important science being done today.”
About CIFAR
The Canadian Institute for Advanced Research builds teams of the best Canadian and international researchers to collaborate on complex questions at the frontiers of human knowledge. CIFAR research is interdisciplinary, collaborative, risky and aimed at creating knowledge with the potential to change how we understand our world.
CIFAR’s Quantum Materials program invents and explores materials whose novel and unusual electronic properties, such as superconductivity, could revolutionize technology.
More about CIFAR:
www.cifar.ca
Read the Nature preprint:
http://lanl.arxiv.org/abs/0909.4430v2
