Eur. Phys. J. B 53, 193-198 (2006)
https://doi.org/10.1140/epjb/e2006-00366-7

Series expansion analysis of a tetrahedral cluster spin chain

Institut für Theoretische Physik, Technische Universität Braunschweig, 38106 Braunschweig, Germany

Corresponding authors: ^a m.arlego@tu-bs.de - ^b w.brenig@tu-bs.de

Received: 24 April 2006
Revised: 21 August 2006
Published online: 6 October 2006

Abstract

Using analytical series expansion by continuous unitary transformations we study the magnetic properties of a frustrated tetrahedral spin- chain. Starting from the limit of isolated tetrahedra we analyze the evolution of the ground state energy and the elementary triplet dispersion as a function of the inter-tetrahedral coupling. The quantum phase diagram is evaluated and is shown to incorporate a singlet product, a dimer, and a Haldane phase. Comparison of our results with those from several other techniques, such as density matrix renormalization group, exact diagonalization, bond-operator theory and other numerical series expansion are provided and convincing agreement is found.