title: Hidden Fermionic Excitation Boosting High-Temperature Superconductivity in Cuprates.
abstract: The dynamics of a microscopic cuprate model, namely, the two-dimensional Hubbard model, is studied with a cluster extension of the dynamical mean-field theory. We find a nontrivial structure of the frequency-dependent self-energies, which describes an unprecedented interplay between the pseudogap and superconductivity. We show that these properties are well described by quasiparticles hybridizing with (hidden) fermionic excitations, emergent from the strong electronic correlations. The hidden fermion enhances superconductivity via a mechanism distinct from a conventional boson-mediated pairing, and originates the normal-state pseudogap. Though the hidden fermion is elusive in experiments, it can solve many experimental puzzles.
authors.affiliation: Department of Applied Physics, University of Tokyo, Hongo, Tokyo 113-8656, Japan.|Center for Emergent Matter Science, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Sakai
authors.affiliation: Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex, France.
authors.forename: Marcello
authors.initials: M
authors.lastname: Civelli
authors.affiliation: Department of Applied Physics, University of Tokyo, Hongo, Tokyo 113-8656, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Imada