According to A.A. Abrikosov а high T_c in cuprates is caused by the presence of an extended van Hove singularity (EVHS) near the Fermi level. In Abrikosov's model, optical phonons with small wave vectors р1ау a dominant role in pairing. In the present investigation the intrinsic Josephson effect in nanosteps (up to 30 nm) on the cryogenically cleaved  surfaces of doped Bi-2212 single crystals has been studied. The obtained results support a previously observed scaling of a superconducting gap and a critical temperature. We have registered a sharp extra structure in the CVC’s of perfect Bi-2212 nanosteps which could be caused by the presence of the EVHS close the Fermi level in slightly overdoped and slightly underdoped samples. An interaction between АС Josephson current and Raman-active phonon modes in the entire range of phonon frequencies (up to 20 THz) was observed in doped Bi-2212. It has been found that the structure related to generation of optical phonon modes can be observed in both underdoped апd overdoped samples, with the doping level having only а negligible effect on the frequency of the main phonon modes. This means that the electron-phonon coupling in BSCCO does not change significantly over the entire region where superconductivity exists.

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1. Evidence for strong electron-phonon interaction in doped Bi-2212 from Josephson spectroscopy
2. Scaling of superconducting gap and critical temperature in doped Bi-2212, Bi-2201 and Hg-1201