Theory of phase fluctuating d-wave superconductors and the spin response   in underdoped cuprates
  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. 
Igor F. Herbut and Dominic J. Lee (Simon Fraser University)