Theory of phase fluctuating d-wave superconductors and the spin response in underdoped cuprates

TL;DR

This paper develops a theoretical framework for understanding the spin response in underdoped cuprates, linking vortex fluctuations in d-wave superconductors to spin-density-wave instabilities and neutron scattering observations.

Contribution

It introduces a minimal theory coupling gapless quasiparticles to vortex fluctuations, revealing a superconductor-insulator transition and spin response characteristics.

Findings

Identifies a superconductor-insulator phase transition driven by vortex proliferation.

Shows the theory reduces to QED3 with a spin-density-wave instability.

Provides computed spin-spin correlations consistent with neutron scattering data.

Abstract

The minimal theory of spin of gapless quasiparticles coupled to fluctuating vortex defects in the phase of the d-wave superconducting order parameter at T=0 is studied. With the proliferation of the vortex loops the theory reduces to the previuosly studied QED3, with its concomitant spin-density-wave (chiral) instability. We find a single superconductor-insulator phase transition, which may be fluctuation induced first-order, at which vortices condense and the chiral symmetry for fermions dynamically breaks. We compute the spin-spin correlation function deep in the fluctuating superconducting state, and discuss some prominent trends in the neutron scattering data on underdoped cuprates in light of our results.