Polaron Coherence as Origin of the Pseudogap Phase in High Temperature Superconducting Cuprates

TL;DR

This paper proposes that polaron ordering causes the pseudogap phase in high-temperature cuprate superconductors, with isotope effects and ion displacement behaviors supporting this theory.

Contribution

It introduces a two-component model linking polaron coherence to the pseudogap, highlighting the role of polaron ordering and mixed s-wave and d-wave order parameters.

Findings

Prediction of a significant isotope effect on pseudogap temperature.

Explanation of ion displacement anomalies through s-wave superconducting component.

Identification of polaron ordering as the pseudogap origin.

Abstract

Within a two component approach to high Tc copper oxides including polaronic couplings, we identify the pseudogap phase as the onset of polaron ordering. This ordering persists in the superconducting phase. A huge isotope effect on the pseudogap onset temperature is predicted and in agreement with experimental data. The anomalous temperature dependence of the mean square copper oxygen ion displacement observed above, at and below Tc stems from an s-wave superconducting component of the order parameter, whereas a pure d-wave order parameter alone can be excluded.