Translation Invariant Bipolarons and Charge Density Waves in High-Temperature Superconductors

TL;DR

This paper links charge density waves and translation invariant bipolarons in high-temperature superconductors, showing how CDWs originate from TI-bipolaron states and coexist with superconductivity, influencing the pseudogap phase and transition behavior.

Contribution

It establishes a theoretical connection between CDWs and TI-bipolarons, explaining their origin and coexistence in the pseudogap phase of high-temperature superconductors.

Findings

CDWs originate from TI-bipolaron states due to Kohn anomaly.

CDWs form a pair density wave at nesting wave vectors.

CDWs coexist with superconductivity and vanish at zero temperature.

Abstract

A correlation is established between the theories of superconductivity based on the concept of charge density waves (CDW) and the translation invariant (TI) bipolaron theory. It is shown that CDW are originated from TI-bipolaron states in the pseudogap phase due to Kohn anomaly and form a pair density wave (PDW) for wave vectors corresponding to nesting. Emerging in the pseudogap phase, CDW coexist with superconductivity at temperatures below that of superconducting transition while their wave amplitudes decrease as a Bose condensate is formed from TI-bipolarons, vanishing at zero temperature.