We investigate mesoscopic Josephson junction arrays created by patterning
superconducting disks on monolayer graphene, concentrating on the high-T/Tc
regime of these devices and the phenomena which contribute to the
superconducting glass state in diffusive arrays. We observe features in the
magnetoconductance at rational fractions of flux quanta per array unit cell,
which we attribute to the formation of flux-quantized vortices. The applied
fields at which the features occur are well described by Ginzburg-Landau
simulations that take into account the number of unit cells in the array. We
find that the mean conductance and universal conductance fluctuations are both
enhanced below the critical temperature and field of the superconductor, with
greater enhancement away from the graphene Dirac point.This work was financially supported by the Engineering
and Physical Sciences Research Council,
and an NPL/EPSRC Joint Postdoctoral Partnership
(RG61493).This is the accepted manuscript. The final version is available at http://journals.aps.org/prb/abstract/10.1103/PhysRevB.91.245418
