Droplet states in quantum XXZ spin systems on general graphs

Academic Article

Abstract

  • © 2018 Author(s). We study XXZ spin systems on general graphs. In particular, we describe the formation of droplet states near the bottom of the spectrum in the Ising phase of the model, where the Z-term dominates the XX-term. As key tools, we use particle number conservation of XXZ systems and symmetric products of graphs with their associated adjacency matrices and Laplacians. Of particular interest to us are strips and multi-dimensional Euclidean lattices, for which we discuss the existence of spectral gaps above the droplet regime. We also prove a Combes-Thomas bound which shows that the eigenstates in the droplet regime are exponentially small perturbations of strict (classical) droplets.
  • Published In

    Digital Object Identifier (doi)

    Author List

  • Fischbacher C; Stolz G
  • Volume

  • 59
  • Issue

  • 5