ISSN:
1434-6036
Keywords:
PACS. 71.10.Fd Lattice fermion models (Hubbard model, etc.) - 75.30.Et Exchange and superexchange interactions - 64.60.-i General studies of phase transitions
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract: An effective intra- and inter-ladder charge-spin Hamiltonian for the quarter-filled ladder compound α'-NaV2O5 has been derived by using the standard canonical transformation method. In the derivation, it is clear that a finite inter-site Coulomb repulsion is needed to get a meaningful result otherwise the perturbation becomes ill-defined. Various limiting cases depending on the values of the model parameters have been analyzed in detail and the effective exchange couplings are estimated. We find that the effective intra-ladder exchange may become ferromagnetic for the case of zig-zag charge ordering in a purely electronic model. We estimate the magnitude of the effective inter-rung Coulomb repulsion in a ladder and find it to be about one-order of magnitude too small in order to stabilize charge-ordering.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s100510070028
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