Eur. Phys. J. B 21, 191-204 (2001)
https://doi.org/10.1007/s100510170195

Exact diagonalization of the S = 1/2 XY ferromagnet on finite bcc lattices to estimate T = 0 properties on the infinite lattice

¹ Institute für Theoretische Physik, Universität Magdeburg, PO Box 4120, 39016 Magdeburg, Germany
² Department of Physics, Dalhousie University, Halifax, NS, B3H 3J5, Canada

Corresponding author: ^a flynnjs@is2.dal.ca

Received: 1 August 2000
Revised: 22 December 2000
Published online: 15 May 2001

Abstract

In this paper finite bcc lattices are defined by a triple of vectors in two different ways -upper triangular lattice form and compact form. In Appendix A are lists of some 260 distinct and useful bcc lattices of 9 to 32 vertices. The energy and magnetization of the S = 1/2 XY ferromagnet have been computed on these bcc lattices in the lowest states for S_z=0, 1/2, 1 and 3/2. These data are studied statistically to fit the first three terms of the appropriate finite lattice scaling equations. Our estimates of the T = 0 energy and magnetization agree very well with spin wave and series expansion estimates.