  Conventional superconductors are strong diamagnets that through the Meissner
effect expel magnetic fields. It would therefore be surprising if a
superconducting ground state would support spontaneous magnetics fields. Such
time-reversal symmetry broken states have been proposed for the
high-temperature superconductors, but their identification remains
experimentally controversial. Here we show a route to a low-temperature
superconducting state with broken time-reversal symmetry that may accommodate
currently conflicting experiments. This state is characterised by an unusual
vortex pattern in the form of a necklace of fractional vortices around the
perimeter of the material, where neighbouring vortices have opposite current
circulation. This vortex pattern is a result of a spectral rearrangement of
current carrying states near the surfaces.
