14 DAY TRIAL // Although first discovered nearly one century ago, superconductivity is still mostly a mystery when it comes to materials such as copper oxides and high temperature superconductors. However, while low temperature superconductors do not present too much importance regarding every day life applications, high temperature superconductors could potentially revolutionize the way we use electricity in electric current generation, transport and distribution as well as other applications like MAGLEV or MRI.
Researchers have been struggling for years to understand how low temperature superconductors work and are still doing so in the case of certain materials. With high temperature superconductors progress has been even slower. University of Cambridge researchers now claim to have identified yet another key component to understanding how high temperature superconductors work and how they can be tweaked in order to function at room temperature.
Most high temperature superconductors are ceramic materials that act as insulators in normal temperature conditions. Additionally, before doping, these materials possess magnetic properties and become superconductors when impurities are added. Thus the question is, how can a ceramic insulator with magnetic properties become a superconductor when doped? Apparently, the Cambridge team partially answered this question by revealing the role of impurities in copper-oxide superconductors.
"An experimental difficulty in the past has been accessing the underlying microscopics of the system once it begins to superconduct. Superconductivity throws a manner of 'veil' over the system, hiding its inner workings from experimental probes. A major advance has been our use of high magnetic fields, which punch holes through the superconducting shroud, known as vortices - regions where superconductivity is destroyed, through which the underlying electronic structure can be probed. We have successfully unearthed for the first time in a high temperature superconductor the location in the electronic structure where 'pockets' of doped hole carriers aggregate. Our experiments have thus made an important advance toward understanding how superconducting pairs form out of these hole pockets," says Dr Suchitra E. Sebastian of the University of Cambridge, the leader of the study.
As a result, not only that the size and the location of the hole pockets have been identified while the material superconducts, but an underlying magnetism phenomenon also seems to influence the shapes of the hole pockets, thus establishing a complex relation between magnetism and superconductivity.
However, there are still a lot of questions that remain to be answered before completely understanding how high temperature superconductivity works, such as where the magnetism appears when the material stops superconducting or what exactly is the mechanism connecting magnetism and superconductivity?