Phonon contribution on the high Tc Cooper pairing investigated by tunnelling spectroscopy

Abstract Improved tunneling spectroscopy on BSCCO(2212) single crystal provided certain spectrum of quasiparticles that mediate the strong Cooper pairing, and it reveals that optical phonons due to the oxygen oscillations in and around the [CuO 2 ] net-plane play a significant role. The elucidated electron-phonon coupling intensities α 2 F (ω) shows an exceeding peak at 72 meV of the breathing mode relating to the charge fluctuations rather than at 35 meV of the B 1g mode which may enhance the spin correlation. Beyond the single phonon energy range ħω D , further significant spectrum peaks was observed and their characteristic energies were assigned in terms of ɛ 0 = 72 meV as n ɛ 0 + ħω ph .