Phys. Rev. Lett. 100, 066403 (2008) [4 pages]Absence of Hole Confinement in Transition-Metal Oxides with Orbital DegeneracyReceived 3 August 2007; published 13 February 2008 We investigate the spectral properties of a hole moving in a two-dimensional Hubbard model for strongly correlated t2g electrons. Although superexchange interactions are Ising-like, a quasi-one-dimensional coherent hole motion arises due to effective three-site terms. This mechanism is fundamentally different from the hole motion via quantum fluctuations in the conventional spin model with SU(2) symmetry. The orbital model describes also propagation of a hole in some eg compounds, and we argue that orbital degeneracy alone does not lead to hole self-localization. © 2008 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.100.066403
DOI:
10.1103/PhysRevLett.100.066403
PACS:
71.10.Fd, 72.10.Di, 72.80.Ga, 79.60.−i
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