Abstract
We investigate the doped perovskite manganites by using some elementary strong-correlation models. We focus mainly on the electronic motion through double-exchange and include the spin and lattice fluctuations solely to lift any residual degeneracy. We consider the low-energy physics of the strong-coupling limit, incorporating the spatial structure of the orbitals carefully. Due to a mismatch between the point-symmetries of the orbitals and the lattice, we find a highly geometrically frustrated Hubbard-like model. When orbital superexchange is dominant, the system finds ordering very difficult, and when the charge-carrier motion is dominant, the styles of orbital order are expected to be fairly complicated. Unless the system exhibits Fermi-liquid behaviour, the strong correlations are suggested to be uncontrollable at present.
Original language | English |
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Pages (from-to) | 1493-1515 |
Number of pages | 23 |
Journal | Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |
Volume | 356 |
Issue number | 1742 |
DOIs | |
Publication status | Published - 15 Jul 1998 |