Professor Nigel Hussey from Bristol University will discuss how despite having been discovered over 100 years ago, superconductivity ,the ability to transport electrical current with no loss of energy, remains one of the most widely studied phenomena of the modern era.
Unfortunately, superconductivity is predominantly a low-temperature phenomenon, which basically means that it costs money to access its unique state of perpetual motion. For a long time, superconductivity could only be observed by plunging the material in question into liquid helium, a very expensive cryogen of limited resource. The advent of high temperature superconductors in 1986, so called as they were found to superconduct above the boiling point of liquid nitrogen, a much cheaper cryogen, caused worldwide excitement and raised expectations that a room temperature superconductor would soon be found. In the intervening years, however no other family of materials have been discovered with such elevated superconducting transition temperatures, and so the wait goes on.
In this talk, he will discuss lessons that have been learned from his own group’s studies of these high-temperature superconductors and why the quest for room-temperature superconductivity may still be a long way from fruition. Specifically, his Group in Bristol have discovered that when a particular material exhibits maximal superconducting tendencies, the electrons in their metallic, non-superconducting state start to become sluggish or even localize around individual atomic sites which in turn causes the superconductivity to collapse. It is as though the interaction that first promotes high temperature superconductivity ultimately destroys the very electronic states from which the superconducting pairs form. This is their Catch 22 conundrum. Now the big question is to identify just what that interaction is and how might it be possible to get around these self-destructive tendencies
Non-members welcome – Admission Free – Refreshments from 7:00pm