Observation of Caroli–de Gennes–Matricon Vortex States in YBa2Cu3O7−δ

The copper oxides present the highest superconducting temperature and properties at odds with other compounds, suggestive of a fundamentally different superconductivity. In particular, the Abrikosov vortices fail to exhibit localized states expected and observed in all clean superconductors. We have explored the possibility that the elusive vortex-core signatures are actually present but weak. Combining local tunneling measurements with large-scale theoretical modeling, we positively identify the vortex states in YBa2Cu3O7−δ. We explain their spectrum and the observed variations thereof from one vortex to the next by considering the effects of nearby vortices and disorder in the vortex lattice. We argue that the superconductivity of copper oxides is conventional, but the spectroscopic signature does not look so because the superconducting carriers are a minority.Received 19 June 2017DOI:https://doi.org/10.1103/PhysRevLett.119.237001© 2017 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasLocal density of statesVortices in superconductorsd-wavePhysical SystemsHigh-temperature superconductorsTechniquesBogoliubov-de Gennes equationsScanning tunneling spectroscopyCondensed Matter, Materials & Applied Physics