Superconducting properties of a two-dimensional doped semiconductor

Анотація

In this paper, we study the superconducting properties of a two-dimensional model with an additional (insulating) gap Δ_ins, which depends on temperature and doping. In particular, we study the doping evolution of the Berezinskii–Kosterlitz–Thouless critical temperature T_c and the superconducting pseudogap temperature T_c^MF at different values of Δ_ins by taking into account the hydrodynamic fluctuations of the superconducting order parameter. We demonstrate that the presence of the gap Δ_ins affect the values of the superconducting gap and temperatures T_c and T_c^MF in the region of the carrier densities where the gap Δ_ins approaches to zero. In particular, the derivatives of these quantities have a jump in this region. We discuss possible relevance of the results to high-temperature superconductors.