Fermi arcs as a visible manifestation of pair level of negative-U centers

TL;DR

This paper proposes that Fermi arcs observed in ARPES experiments are caused by interactions between valence electrons and negative-U centers in cuprates, leading to gap vanishing and free hole carrier generation.

Contribution

It introduces a novel explanation linking Fermi arcs to negative-U centers and their interaction with valence electrons in cuprate superconductors.

Findings

Fermi arcs result from two-particle hybridization with negative-U centers.

Transitions to NUCs generate free hole carriers responsible for conduction.

The model explains the observed gap vanishing over parts of the Fermi surface.

Abstract

Here we consider the possibility that the Fermi arcs observed in ARPES experiments result from interaction of valence band electrons with negative-U centers (NUCs) which are formed under doping on the pairs of neighboring Cu cations in CuO2 plane. This interaction results in two-particle hybridization and vanishing of the gap over the part of Fermi contour. Furthermore the transitions of electrons to NUCs result in the generation of free hole carriers. Just these carriers rather than doping induced charges provide conduction in the normal state.