Rotor Spectra, Berry Phases, and Monopole Fields: from Antiferromagnets to QCD

Abstract

The order parameter of a finite system with a spontaneously broken continuous global symmetry acts as a quantum mechanical rotor. Both antiferromagnets with a spontaneously broken $SU(2{)}_s$ spin symmetry and massless QCD with a broken $SU(2{)}_L\times SU(2{)}_R$ chiral symmetry have rotor spectra when considered in a finite volume. When an electron or hole is doped into an antiferromagnet or when a nucleon is propagating through the QCD vacuum, a Berry phase arises from a monopole field and the angular momentum of the rotor is quantized in half-integer units.

4 pages

References in corpus (1)

• Two-Hole Bound States from a Systematic Low-Energy Effective Field Theory for Magnons and Holes in an Antiferromagnet

Cited by in corpus (5)

• Effective theory for deformed nuclei
• Non-Abelian Monopole in the Parameter Space of Point-like Interactions
• Effective field theories for collective excitations of atomic nuclei
• Broken Symmetry and Fractionalized Flux Strings in a Staggered U(1) Pure Gauge Theory
• Supersymmetry and non-Abelian geometric phase for a free particle on a circle with point-like interactions