Incommensuration in quantum antiferromagnetic chain

Abstract

A dimerized quantum Heisenberg or XY antiferromagnetic chain has a gap in the spectrum. We show that a weak incommensurate modulation around a dimerized chain produces a zero temperature quantum critical point. As the incommensuration wavelength is varied, there is a transition to a modulated gapless state. The critical behaviour is in the universality class of the classical commensurate-incommensurate (Pokrovsky-Talapov) transition. An analogous metal-insulator transition can also take place for an incommensurate chain.

5 pages, revtex, no figures, to appear in J. Phys A Letters

References in corpus (1)

• A numerical study of the Random Dimerized XX spin-1/2 chain

Cited by in corpus (4)

• Thermodynamic properties of the periodic nonuniform spin-1/2 isotropic XY chains in a transverse field
• Low-energy properties of two-leg spin-1 antiferromagnetic ladders with commensurate external fields and their extensions
• One-dimensional fermions with incommensuration
• One-dimensional fermions with incommensurate hopping close to dimerization