Local particle-hole pair excitations by SU(2) symmetry fluctuations

TL;DR

This paper proposes a new theoretical framework for the pseudogap phase in cuprate superconductors, attributing it to local particle-hole pairs from SU(2) symmetry fluctuations, explaining Fermi arcs and charge modulations observed experimentally.

Contribution

It introduces a novel theory linking SU(2) symmetry fluctuations to local particle-hole pairs, providing insights into pseudogap phenomena and experimental charge modulations.

Findings

Accounts for the robustness of the pseudogap phase.

Explains the formation of Fermi arcs.

Predicts charge modulations consistent with experiments.

Abstract

Understanding the pseudo-gap phase which opens in the under-doped regime of cuprate superconductors is one of the most enduring challenges of the physics of these compounds. A depletion in the electronic density of states is observed, which is gapping out part of the Fermi surface, leading to the formation of mysterious lines of massless excitations- the Fermi arcs. Here we give a new theoretical account of the physics of the pseudo-gap phase in terms of the emergence of local patches of particle-hole pairs generated by SU(2) symmetry fluctuations. The proliferation of these local patches accounts naturally for the robustness of the pseudo-gap phase to disturbances like disorder or magnetic field and is shown to gap out part fo the Fermi surface, leading to the formation of the Fermi arcs. Most noticeably, we show that these patches induce a modulated charge distribution on the Oxygen atoms, in remarkable agreement with recent X-ray and STM observations.