Synergetic Phonon–Spin–Charge Mechanism of High-Temperature Superconductivity

For a long time the majority opinion in the field of high-temperature superconductivity (HTSC) has been that it is purely an electronic phenomenon involving spin, and could be explained by a t–J Hamiltonian. Phonons and local distortion were regarded as irrelevant or harmful to HTSC. However, various experimental results indicate strong phonon involvement and ubiquitous presence of local spin–charge–lattice inhomogeneity. We suggest that the electron–phonon (e–p) coupling in the cuprate is unconventional, and a synergetic coupling of spin, charge, and phonon could explain the HTSC phenomenon. In our view the spin–charge–lattice inhomogeneity is a signature of such a coupling and an important component of the HTSC mechanism.