Location of Repository

Effect of a Staggered Magnetic Field on the S=1 Haldane Chain with Single-ion Anisotropy

By F. Anfuso, E. Ercolessi, G. Mor and M. Roncaglia

Abstract

We analyze the gaps in the excitation spectrum of a Haldane chain with single-ion anisotropy in a staggered field. We show that the gap along the direction of the field increases at a faster rate than the others, while its spectral weight decreases, being transferred to a two-magnon continuum. In recent times the preparation of a new class of magnetic materials of the general formula (RxY1−x)2BaNiO5, where R is one of the magnetic rare-earth ions, has arisen a new theoretical interest for the study of integer-spin Haldane chains in a staggered magnetic field. The reference compound Y2BaNiO5 [1] is one of the best examples of a magnetic material with a singlet ground state and a spin gap which has been interpreted in the framework of the Haldane conjecture [2], according to which integer-spin chains have disordered ground state separated by a gap from a degenerate triplet of excitations. In all these materials [3], the Ni ions are arranged along linear chains (the a-axis of thei

Year: 2008
OAI identifier: oai:CiteSeerX.psu:10.1.1.306.3052
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://citeseerx.ist.psu.edu/v... (external link)
  • http://arxiv.org/pdf/cond-mat/... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.