Phonon mechanism of high-TC superconductivity

The majority opinion in the field of high-temperature superconductivity has long been that it is a purely electronic phenomenon involving only spins. But this view is now seriously challenged by recent experimental observations of strong electron-phonon coupling and nano-scale electronic inhomogeneity. It is possible that the electron-phonon coupling in the cuprates is unconventional and plays a key role in superconductivity. We propose that a real space polaronic pairing involving the Cu-O bond-stretching phonon modes and the electronic states near the van Hove singularity may explain both spatial inhomogeneity and superconductivity.