2004/05/31 by Masahiro Sato
Physics and Astronomy · #Magnetic properties of thin films #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.71.024402
published as Phys. Rev. B 71, 024402 (2005) · 25 pages, 14 figures, REVTeX, final version
openalex publication_date 2005/01/06 · arxiv created 2005/01/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
This study addresses low-energy properties of two-leg spin-1 ladders with antiferromagnetic (AF) intrachain coupling under a uniform or staggered external field H, and a few of their modifications. The generalization to spin-S ladders is also discussed. In the strong AF rung(interchain)-coupling J_\ensuremath⊥ region, degenerate perturbation theory applied to spin-S ladders predicts 2S critical curves in the parameter space (J_\ensuremath⊥,H) for the staggered-field case, in contrast to 2S finite critical regions for the uniform-field case. All critical areas belong to a universality with central charge c=1. On the other hand, we employ Abelian and non-Abelian bosonization techniques in the weak rung-coupling region. They show that in the spin-1 ladder, a sufficiently strong uniform field engenders a c=1 critical state regardless of the sign of J_\ensuremath⊥, whereas the staggered field is expected not to yield any singular phenomena. From the bosonization techniques, new field-theoretical expressions of string order parameters in the spin-1 systems are also proposed.