May 2012:  Prof. Séamus Davis Provides Evidence for Magnetism’s Role in Superconductivity

Energy-saving technologies like zero-loss power transmission lines are the beginning of the promises of high-temperature superconductors and Cornell Professor of Physics J.C. Séamus Davis is getting closer to creating these materials every day.

Most recently, Davis, who is Cirector of the Center for Emergent Superconductivity at Brookhaven National Laboratory, and his group have designed and conducted experiments to measure the role played by electron magnetism in an iron-based superconductor.

Scientists have suggested for years that the key to a superconductor’s ability to carry current without resistance lies in the binding of electrons as Cooper pairs.  However it has not been possible to find Cooper pairs in copper-based superconductors.  New hope for this theory was born when iron-based superconductors were discovered.  Theories abounded but there was no mechanism in existence for testing them.

Cornell post-doctoral researchers Milan Allan and Andreas Rost filled in the gap by devising an experimental method called multi-band Bogoliubov quasiparticle scattering interference.  The results supported what theories had predicted:  the mechanism for superconductivity in iron-based superconductors is due primarily to magnetic interactions.

The tests were conducted on lithium iron arsenide and new experiments will show whether the theory holds true for other iron superconductors.  If further experimentation shows that the theories still hold, a model could then be used to predict the properties of other elements, pointing to new materials and higher-temperature superconductors.

To read the full article in Science, click here.