Ginzburg-Landau theory of a resonating-valence-bond superconductor

Abstract

We present a Ginzburg-Landau formulation of the bosonic resonating-valence-bond (RVB) theory of superconductivity. The superconducting order parameter is characterized by phase vortices that describe spinon excitations and the transition to the superconducting state occurs when such phase vortices (un)bind. We show that the boson RVB theory always leads to $hc/2e$ flux quanta and that the presence of a trapped spin-1/2 moment inside a vortex core gives rise to observable consequences for the low-temperature field-dependent specific heat. We also show that the cores of magnetic fluxoids exhibit enhanced antiferromagnetic correlations with a midgap energy scale and discuss some experimental implications.