Suppression Of The Superconducting Transition Temperature Of Doped Graphene Due To Thermal Fluctuations Of The Order Parameter

In this Brief Report, we analyze the superconducting properties of doped single- and double-layer graphene systems by taking into account the fluctuations of the superconducting order parameter. Our analysis is rather general, and corresponds to a phenomenological electron-electron (hole-hole) attraction defined by its strength and range, and is independent of the origin of attraction. We show that in this model, similar to the case of two-dimensional doped metal, the thermal fluctuations of the order-parameter result in a significant reduction in the Berezinskii-Kosterlitz-Thouless critical temperature Tc comparing to the mean-field temperature Tc MF, and there is a pseudogap phase with a suppressed density of states at temperature range T