Abstract
We investigate the spectral properties of a hole moving in a two-dimensional Hubbard model for strongly correlated 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 compounds, and we argue that orbital degeneracy alone does not lead to hole self-localization.
- Received 3 August 2007
DOI:https://doi.org/10.1103/PhysRevLett.100.066403
©2008 American Physical Society