Pseudogap and (an)isotropic scattering in the fluctuating charge-density wave phase of cuprates

TL;DR

This paper proposes a unified scenario for high-temperature cuprate superconductors, linking dynamical charge density waves, pseudogap phenomena, and anisotropic scattering, with a focus on the role of a CDW quantum critical point.

Contribution

It introduces a comprehensive framework connecting fluctuating CDWs, pseudogap behavior, and scattering anisotropy in cuprates, emphasizing the impact of a CDW quantum critical point.

Findings

CDW fluctuations explain pseudogap temperature T* and CDW onset.

Scattering anisotropy is strongest near the CDW quantum critical point.

Scattering becomes isotropic and marginal-Fermi-liquid-like away from the QCP.

Abstract

We present a general scenario for high-temperature superconducting cuprates, based on the presence of dynamical charge density waves (CDWs) and to the occurrence of a CDW quantum critical point, which occurs, e.g., at doping p~0.16 in YBCO. In this framework, even the pseudogap temperature T* is interpreted in terms of a reduction of the density of states due to incipient CDW and, at lower temperature to the possible formation of incoherent superconducting pairs. The dynamically fluctuating character of CDW accounts for the different temperatures at which the pseudogap (T*), the CDW onset revealed by X-ray scattering (T_{ons}(p)), and the static three-dimensional CDW ordering appear. We also investigate the anisotropic character of the CDW-mediated scattering. We find that this is strongly anisotropic only close to the CDW quantum critical point (QCP) at low temperature and very low energy. It rapidly becomes nearly isotropic and marginal-Fermi-liquid-like away from the CDW QCP and at finite (even rather small) energies. This may reconcile the interpretation of Hall measurements in terms of anisotropic CDW scattering with recent photoemission experiments.