A model of the T-dependent pseudogap and its competition with superconductivity in copp er oxides

TL;DR

This paper presents a band model explaining the pseudogap in copper oxides as a competing phase to superconductivity, influenced by vibrational or magnetic excitations and charge or spin density waves.

Contribution

It introduces a theoretical model linking pseudogap formation to vibrational and magnetic fluctuations and their competition with superconductivity in copper oxides.

Findings

Pseudogaps arise from vibrational or magnetic excitations.

Charge or spin density waves can generate pseudogaps at lower temperatures.

The pseudogap acts as a precursor and competitor to superconductivity.

Abstract

Results for pseudogaps are obtained from a band model, where the stability of the gap depends on the amplitudes of vibrational displacements, or magnetic moments, and their coupling to electrons. A one-particle gap is favored by normal thermal excitations of phonons or spin waves. Another gap can be generated by spontaneous waves at lower temperature, if the electronic energy gain overcomes the elastic/magnetic energy needed for increased amplitudes of the oscillations. This state is characterized by charge or spin density waves. The pseudogap has many features in common with the superconducting gap, and the model lends support to the interpretation that the pseudogap is a precursor of, and competes with, superconducting pairing.