Modeling a striped pseudogap state

TL;DR

This paper models a stripe-ordered pseudogap state in cuprates, revealing how local pairing and stripe order produce a nodal Fermi surface, pseudogap features, and a smooth evolution into superconductivity.

Contribution

It introduces a theoretical model of a stripe-ordered pseudogap state with coexisting spin, charge, and pairing correlations, capturing key experimental features.

Findings

Fermi arc with a hole pocket in the spectral function.

Localized states near the pseudogap energy.

Smooth evolution from pseudogap to superconducting state.

Abstract

We study the electronic structure within a system of phase-decoupled one-dimensional superconductors coexisting with stripe spin and charge density wave order. This system has a nodal Fermi surface (Fermi arc) in the form of a hole pocket and an antinodal pseudogap. The spectral function in the antinodes is approximately particle-hole symmetric contrary to the gapped regions just outside the pocket. We find that states at the Fermi energy are extended whereas states near the pseudogap energy have localization lengths as short as the inter-stripe spacing. We consider pairing which has either local d-wave or s-wave symmetry and find similar results in both cases, consistent with the pseudogap being an effect of local pair correlations. We suggest that this state is a stripe ordered caricature of the pseudogap phase in underdoped cuprates with coexisting spin-, charge-, and pair-density wave correlations. Lastly, we also model a superconducting state which 1) evolves smoothly from the pseudogap state, 2) has a signature subgap peak in the density of states, and 3) has the coherent pair density concentrated to the nodal region.