Evolution of the dynamical pairing across the phase diagram of a strongly correlated high-temperature superconductor

TL;DR

This study investigates how Cooper pairing evolves in a high-temperature superconductor model, revealing a transition from unconventional to conventional pairing and the emergence of a pseudogap, with implications for experimental observations.

Contribution

It provides a detailed analysis of pairing dynamics across the phase diagram of the Hubbard model, highlighting a transition in pairing nature and pseudogap formation.

Findings

Unconventional pairing in over-doped region

Conventional boson-mediated pairing in under-doped region

Pseudogap formation linked to Mott phenomena

Abstract

We study the dynamics of the Cooper pairing across the T=0 phase diagram of the two-dimensional Hubbard Model, relevant for high-temperature superconductors, using a cluster extension of dynamical mean field theory. We find that the superconducting pairing function evolves from an unconventional form in the over-doped region into a more conventional boson-mediated retarded form in the under-doped region of the phase diagram. The boson, however, promotes the rise of a pseudo-gap in the electron density of states rather than a superconducting gap as in the standard theory of superconductivity. We discuss our results in terms of Mott-related phenomena, and we show that they can be observed in tunneling experiments.