Stripes 'play key role' in superconductivity

Science 18 Mar 11 The mysterious hourglass-shaped magnetic spectrum found in high temperature superconductors could be caused by fluctuating magnetic stripes Fluctuating magnetic stripes could be the cause of the mysterious hourglass-shaped magnetic spectrum found in high temperature superconductors, according to new research. Scientists at Oxford University and the Institut Laue-Langevin have used neutrons to probe the magnetic 'glue' thought to produce high temperature superconductivity and have identified stripes of magnetic moments and charge as the cause of a strange hourglass-shaped magnetic spectrum. Current research into the origins of high temperature superconductivity found in a large class of copper oxide compounds centres on the motion of atomic magnetic moments. Fluctuations of these moments are believed to create an attractive force (a sort of magnetic 'glue') which binds electrons in pairs and allows them to move around unimpeded giving rise to superconductivity. Recent debate has focused on the cause of an unusual hourglass shape found in the spectrum of these magnetic fluctuations. The origin of this pattern, which is found in many if not all high temperature superconductors, is thought to relate to an alternating pattern of spin and charge stripes found within the atomic layers but so far it has been hard to prove a link between the two phenomena. The researchers instead turned their attention to an insulating cobalt oxide with a similar magnetic stripe pattern.