Superconducting Density of States in B-Doped Diamond

In the presented work, we investigated the superconducting boron doped diamond polycrystalline film prepared by chemical vapor deposition by means of scanning tunneling microscopy/spectroscopy. Differential conductance spectra measured at various temperatures were used to obtain the values of superconducting critical temperature and energy gap.Comparing various theoretical models fitted to the differential conductance spectra measured at 0.5 K suggests weak pair breaking.However, this cannot account for the high 2∆ k B T C ratio, which therefore indicates strong coupling.