Hidden crystal patchwork in cuprate superconductor upends four decades of theory

Using an advanced scanning 3D X-ray diffraction technique, scientists at the University of Warwick have revealed that a cuprate superconductor long thought to have a homogeneous crystal lattice actually consists of a mosaic of two slightly different atomic configurations. The boundaries separating these domains are far wider than conventional theory predicts, behaving almost like distinct structures that could disrupt the flow of resistance-free current.

Professor Mark Senn, who led the study, noted that this discovery overturns a core assumption that has guided superconductivity research for the past 40 years. The results, appearing in Physical Review Letters, suggest that internal heterogeneity may be responsible for why some cuprate samples outperform others, prompting a re-examination of earlier bulk experiments. The breakthrough was made possible by a recent €150 million upgrade to the European Synchrotron Radiation Facility in France, which provides the intense X-ray beams needed for such detailed interior imaging. The authors propose that similar hidden structures may exist in other cuprates and related high-pressure superconductors, offering a new direction for improving future superconducting technologies.