Superconductor physics

Scientists believe they have come one step closer to understanding the physics behind high-temperature superconductors, following evidence of a link between magnetism and superconductivity.

The discovery was made by researchers at Queen Mary, University of London and the Fribourg University in Switzerland, who detailed the behaviour of new high-temperature superconductors known as oxypnictides.

Their work found that, like their copper-oxide equivalent, superconductivity in oxypnictides emerged from a magnetic state.

The physics behind high-temperature superconductivity (operating at around -130oC) has remained a mystery since it was first discovered in copper-oxides in 1986.

However, Dr Alan Drew from Queen Mary’s Department of Physics and his research partners at the University of Fribourg believe that their findings could be significant in understanding the way in which high temperature superconductors work.

Dr Drew said: ‘Last year a new class of high-temperature superconductor was discovered that has a completely different make-up to the ones previously known – containing layers of arsenic and iron instead of layers of copper and oxygen.

‘Our hope is that by studying them both together, we may be able to resolve the underlying physics behind both types of superconductor and design new superconducting materials, which may eventually lead to even higher temperature superconductors.’

Professor Bernhard, from the University of Fribourg, added: ‘Despite the mysteries of high-temperature superconductivity, their applications are wide-ranging.

‘One exciting applications is using superconducting wire to provide lossless power transmission from power stations to cities.

‘Superconducting wire can hold a much higher current density than existing copper wire and is lossless and therefore energy saving.’

An electrical current flowing round a loop of superconducting wire can continue indefinitely, producing exceptionally powerful electromagnets.

These magnets are used in MRI scanners, to ‘float’ the Maglev train, and to steer the proton beam of the Large Hadron Collider (LHC) at CERN.

Future applications of superconductors could extend to ultrafast electronic devices and quantum computing.