17 February 2014

An international team led by three physicists from the Université de Sherbrooke recently succeeded in solving an enigma in the field of superconductivity that has existed for the past 20 years. Their major discovery has just been published in the prestigious journal Nature Communications.

» Go to the article in Nature Communications

Gaël Grissonnanche, PhD candidate in physics and lead author of the study, Louis Taillefer, holder of the Canada Research Chair in Quantum Materials and the study’s senior investigator, and Nicolas Doiron-Leyraud, professor in the Physics Department, along with international colleagues, have identified one of the main mechanisms limiting the critical temperature at which cuprates transition into a superconductive state.

Gaël Grissonnanche, Nicolas Doiron-Leyraud and Louis Taillefer

Cuprates are copper oxides and are proving to be the most promising superconductive materials. They become superconductors – i.e., they conduct electrical current with no resistance – at -150 °C, which is the “highest” known temperature at which this occurs.

Thanks to equipment designed in Sherbrooke, the team of scientists succeeded in measuring the critical magnetic field of cuprates, an international first.

Surprise: the Sherbrooke physicists observed a phenomenon confirming that the drop in critical temperature is caused by the sudden appearance of a distinct electronic phase that enters into competition with the superconductivity.

This major discovery paves the way for new paths to be developed to increase the critical temperature of superconductors. “If this state could persist at ambient temperature, it would profoundly transform our technological world,” noted Louis Taillefer.

Source: Université de Sherbrooke