1 research outputs found
Deformed strings in the Heisenberg model
We investigate solutions to the Bethe equations for the isotropic S = 1/2
Heisenberg chain involving complex, string-like rapidity configurations of
arbitrary length. Going beyond the traditional string hypothesis of undeformed
strings, we describe a general procedure to construct eigenstates including
strings with generic deformations, discuss general features of these solutions,
and provide a number of explicit examples including complete solutions for all
wavefunctions of short chains. We finally investigate some singular cases and
show from simple symmetry arguments that their contribution to zero-temperature
correlation functions vanishes.Comment: 34 pages, 13 figure