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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 2 Issue 4 (1998) pp 457-461
A scenario for the electronic state in the manganese perovskites: the orbital correlated metal
M.J. Rozenberg (a)
Institut Laue-Langevin, BP156, 38042 Grenoble, France
Received: 3 October 1997 / Revised: 9 December 1997 / Accepted: 12 January 1998
Abstract: We propose a novel scenario for the electronic state in the manganese perovskites. We argue that, at low temperatures and within the ferromagnetic state, the physics of these colossal magnetoresistance compounds may be characterized by a correlated metallic state near a metal insulator transition where the orbital degrees of freedom play the main role. This follows from the observation that a two-band degenerate Hubbard model under a strong magnetic field can be mapped onto a para-orbital single band model. We solve the model numerically using the quantum Monte-Carlo technique within a dynamical mean field theory which is exact in the limit of large lattice connectivity. We argue that the proposed scenario may allow for the qualitative interpretation of a variety of experiments which were also observed in other (early) transition metal oxides.
PACS. 75.50.Cc Other ferromagnetic metals and alloys - 72.10.Fk Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect) - 71.20.Be Transition metals and alloys
(a) email: marcelo@ill.fr
Online publication: June 2, 1998
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