Physikalisches Institut, Universit?t Bayreuth, 95440 Bayreuth, Germany, DE Institut für Theoretische Physik, Universit?t zu K?ln, 50937 K?ln, Germany, DE
Abstract:
In the past different models for the magnetic salt vanadyl pyrophosphate (VO)2P2O7 were discussed. Neither a spin ladder nor an alternating chain are capable to describe recently measured magnetic excitations.
In this paper we propose a 2D model that fits better to experimental observations.
Received: 29 May 1998 / Received in final form: 25 September 1998 / Accepted: 30 September 1998