  High temperature cuprate superconductors exhibit extremely local nanoscale
phenomena and strong sensitivity to doping. While other experiments have looked
at nanoscale interfaces between layers of different dopings, we focus on the
interplay between naturally inhomogeneous nanoscale regions. Using scanning
tunneling microscopy to carefully track the same region of the sample as a
function of temperature, we show that regions with weak superconductivity can
persist to elevated temperatures if bordered by regions of strong
superconductivity. This suggests that it may be possible to increase the
maximum possible transition temperature by controlling the distribution of
dopants.
