Valence bond glass -- A unified theory of electronic disorder and pseudogap phenomena in high temperature superconductors

TL;DR

This paper presents a unified theory explaining how valence bond fluctuations, pinned by electronic disorder, lead to pseudogap phenomena and Fermi arc formation in underdoped high-T_c cuprates, highlighting the interplay of strong correlations and disorder.

Contribution

It introduces a valence bond glass model that unifies the understanding of electronic disorder and pseudogap phenomena in high-temperature superconductors.

Findings

Antinodal Fermi surface sections are gapped, forming Fermi arcs.

Superexchange interactions induce a d-wave superconducting gap below T_c.

The theory captures doping and temperature dependence of pseudogap features.

Abstract

We show that the low-energy fluctuations of the valence bond in underdoped high-T_c cuprates, originating from quantum fluctuations of the superexchange interaction, are pinned by the electronic disorder due to off-stoichiometric dopants, leading to a valence bond glass (VBG) pseudogap phase. The antinodal Fermi surface sections are gapped out, giving rise to a normal state Fermi arc whose length shrinks with underdoping. Below T_c, the superexchange interaction induces a d-wave superconducting gap that coexists with the VBG pseudogap. The evolution of the local and momentum-space spectroscopy with doping and temperature captures the salient properties of the pseudogap phenomena and the electronic disorder. The unified theory elucidates the important interplay between strong correlation and the intrinsic electronic disorder in doped transition metal oxides.