Numerical exact diagonalization study on a phonon-assisted hole paring in the high- cuprates

Sakai, Toru

In our previous study on the -Holstein model including the breathing and buckling vibrations of the in-plane oxygen atoms, the suppression of hole pairing by the breathing mode was indicated, while the buckling mode was revealed to assist it. In the present study, we take the renormalization of the hole hopping parameter t due to the phonon effect into account and reconsider the phonon-assisted hole pairing mechanism. It is found that even the breathing vibration of in-plane oxygen can enhance the hole binding for some realistic parameters.