TY - JOUR
T1 - Charge- and magnetic-ordering in a two-orbital double-exchange model for manganites
AU - Jackeli, G.
AU - Perkins, N.
AU - Plakida, N.
PY - 2000
Y1 - 2000
N2 - The phase diagram of half-doped perovskite manganites is studied within the extended double-exchange model. To demonstrate the role of orbital degrees of freedom both one- and two-orbital models are examined. A rich phase diagram is obtained in the mean-filed theory at zero temperature as a function of J [antiferromagnetic (AFM) superexchange interaction] and V (intersite Coulomb repulsion). For the one-orbital model a charge-ordered (CO) state appears at any value of V with different types of magnetic order which changes with increasing J from ferromagnetic (F) to AFM ones of the types A, C, and G. The orbital degeneracy results in appearance of a new CE-type spin order that is favorable due to opening of the “dimerization” gap at the Fermi surface. In addition, the CO state appears only for (Formula presented) for F and CE states while the C-type AFM state disappears and A-type AFM state is observed only at small values of V as a charge disordered one. The relevance of our results to the experimental data are discussed.
AB - The phase diagram of half-doped perovskite manganites is studied within the extended double-exchange model. To demonstrate the role of orbital degrees of freedom both one- and two-orbital models are examined. A rich phase diagram is obtained in the mean-filed theory at zero temperature as a function of J [antiferromagnetic (AFM) superexchange interaction] and V (intersite Coulomb repulsion). For the one-orbital model a charge-ordered (CO) state appears at any value of V with different types of magnetic order which changes with increasing J from ferromagnetic (F) to AFM ones of the types A, C, and G. The orbital degeneracy results in appearance of a new CE-type spin order that is favorable due to opening of the “dimerization” gap at the Fermi surface. In addition, the CO state appears only for (Formula presented) for F and CE states while the C-type AFM state disappears and A-type AFM state is observed only at small values of V as a charge disordered one. The relevance of our results to the experimental data are discussed.
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U2 - 10.1103/PhysRevB.62.372
DO - 10.1103/PhysRevB.62.372
M3 - Article
AN - SCOPUS:0000972136
SN - 1098-0121
VL - 62
SP - 372
EP - 378
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 1
ER -