Homogeneous versus Spiral Phases of Hole-doped Antiferromagnets: A Systematic Effective Field Theory Investigation

TL;DR

This paper uses effective field theory to analyze the phases of hole-doped antiferromagnets, identifying conditions under which homogeneous or spiral magnetic phases are energetically favored.

Contribution

It systematically investigates the phase diagram of doped antiferromagnets using an effective field theory approach, highlighting the conditions for different magnetic phases.

Findings

Homogeneous phase is favored at certain parameters.

Spiral phase becomes energetically preferred under specific conditions.

Doping reduces the staggered magnetization.

Abstract

Using the low-energy effective field theory for magnons and holes -- the condensed matter analog of baryon chiral perturbation theory for pions and nucleons in QCD -- we study different phases of doped antiferromagnets. We systematically investigate configurations of the staggered magnetization that provide a constant background field for doped holes. The most general configuration of this type is either constant itself or it represents a spiral in the staggered magnetization. Depending on the values of the low-energy parameters, a homogeneous phase, a spiral phase, or an inhomogeneous phase is energetically favored. The reduction of the staggered magnetization upon doping is also investigated.