2008/06/27 by I. Maruyama, Isao Maruyama, T. Hirano +3
Mathematics · Physics and Astronomy · #Adiabatic process #Combinatorics #Excited state #Geometric phase #Invariant (physics) #Mathematics #Phase (matter) #Physics #Physics of Superconductivity and Magnetism #Quantum many-body systems #Quantum mechanics #Singlet state #Topological Materials and Phenomena #Topology (electrical circuits) #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.79.115107
5 pages, 4 figures
arxiv created 2008/06/27 · openalex publication_date 2009/03/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A spin-(1)/(2) two-leg ladder with four-spin ring exchange is studied by quantized Berry phases, used as local-order parameters. Reflecting local objects, nontrivial (\ensuremathπ) Berry phase is founded on a rung for the rung-singlet phase and on a plaquette for the vector-chiral phase. Since the quantized Berry phase is topologically invariant for gapped systems with the time-reversal symmetry, topologically identical models can be obtained by the adiabatic modification. The rung-singlet phase is adiabatically connected to a decoupled rung-singlet model and the vector-chiral phase is connected to a decoupled vector-chiral model. Decoupled models reveal that the local objects are a local singlet and a plaquette singlet, respectively.