Evidence of vortices and mixed-state superconductivity in phosphorus-doped graphene. Part II (Hysteresis).

We have observed indications of possible superconductivity in phosphorus-doped graphene. In the past we focused on resistivity and susceptibility measurements in our doped graphene samples. There are also magnetic-induced phenomena in phosphorus-doped multilayer graphene that are consistent with effects observed in type II multilayer superconductors. Such effects include Nernst peaks in the presence of magnetic fields, vortex and charge BKT transitions as well as well-defined hysteresis curves in the cooling and warming Nernst plots. In this work, we present the results of our experiments and provide explanations of the role of vortices as well as vortex-antivortex dissociation as the cause of the hysteresis found in the Nernst plots. [ABSTRACT FROM AUTHOR]