arXiv:cond-mat/0007447 · Physical review. B, Condensed matter
Single-hole dynamics in dimerized and frustrated spin chains
Christoph Jurecka, Wolfram Brenig
Abstract
We present a unified account for the coupled single-hole and spin dynamics in the spin-gap phase of dimerized and frustrated spin chains and two-leg spin ladders. Based on the strong dimer limit of a one-dimensional ${t}_{1,2,3}$-${J}_{1,2,3}$ model a diagrammatic approach is presented that employs a mapping of the spin Hamiltonian onto a pseudofermion bond-boson model. Results for the single-hole spectrum are detailed. A finite quasiparticle weight is observed and studied for a variety of system parameters. A comparison with existing exact-diagonalization data is performed and good agreement is found.