Correlation between T_c and the Cu 4s level reveals the mechanism of high-temperature superconductivity

Abstract

Band structure trends in hole-doped cuprates and correlations with T_c are interpreted within the s--d exchange mechanism of high-T_c superconductivity. The dependence of T_c on the position of the copper 4s level finds a natural explanation in the generic Cu 3d, Cu 4s, O 2p_x and O 2p_y four-band model. The Cu 3d--Cu 4s intra-atomic exchange interaction is incorporated in the standard BCS scheme. This dependence of T_c in the whole interval of 25--125 K has no alternative explanation at present, and possibly this quarter of a century standing puzzle is already solved.

7 pages, 2 figures, Special Issue of Bulgarian Journal of Physics in Memoriam Academician Professor Matey Mateev, one new reference in the second version, correct pages in the journal version are cited

Cited by in corpus (1)

• Kondo $s$-$d$ exchange in the CuO${}_2$ plane as the long sought interaction determining $T_c$ in cuprates