Staggered-flux normal state in the weakly doped t-J model

TL;DR

This paper investigates the normal state of the t-J model near half-filling, showing that a staggered-flux order is energetically favored and may be relevant for vortex cores in underdoped cuprates, providing insights into their microscopic properties.

Contribution

It introduces a variational approach demonstrating the stability of a staggered-flux state in the t-J model at low doping, linking it to experimental phenomena in cuprates.

Findings

Staggered-flux state is energetically favored near half-filling.

Estimated superfluid density and coherence length from the wave function.

Comparison of energies suggests relevance to vortex core physics.

Abstract

A normal (non-superconducting) ground state of the t-J model may be variationally approximated by a Gutzwiller-projected wave function. Within this approximation, at small hole doping near half-filling, the normal state favors staggered-flux ordering. Such a staggered-flux state may occur in vortex cores of underdoped high-temperature cuprate superconductors. From comparing the energies of the staggered-flux state and of the superconducting state, we numerically obtain the condensation energy. Extracting the superfluid density directly from the projected superconducting wave function, we can also estimate the coherence length at zero temperature.