H. Mohrbach1 - A. Bérard1 - P. Gosselin2
1 L.P.L.I. Institut de Physique, 1 blvd D.Arago, 57070 Metz, France
2 Université Grenoble I, Institut Fourier, UMR 5582 CNRS-UJF, UFR de Mathématiques, BP74, 38402 Saint Martin d'Hères, Cedex, France
Received: 26 June 2000 / Published online: 31 August 2000 - © Springer-Verlag 2000
It is shown that next-nearest-neighbor interactions may lead to unusual paramagnetic or ferromagnetic phases which physical content is radically different from the standard phases. Actually there are several particles described by the same quantum field in a manner similar to the species doubling of the lattice fermions. The renormalizability of the theory is proven at the one loop level.
Copyright Società Italiana di Fisica, Springer-Verlag 2000