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arXiv · 1505.01498

Holon-Doublon Binding as the Mechanism for the Mott transition

Peter Prelovšek·Jure Kokalj·Zala Lenarčič·Ross H. McKenzie
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Abstract

We study the binding of a holon to a doublon in a half-filled Hubbard model as the mechanism of the zero-temperature metal-insulator transition. In a spin polarized system and a non-bipartite lattice a single holon-doublon (HD) pair exhibits a binding transition (e.g., on a face-centred cubic lattice), or a sharp crossover (e.g., on a triangular lattice) corresponding well to the standard Mott transition in unpolarized systems. We extend the HD-pair study towards non-polarized systems by considering more general spin background and by treating the finite HD density within a BCS-type approximation. Both approaches lead to a discontinuous transition away from the fully polarized system and give density correlations consistent with numerical results on a triangular lattice.

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Peter Prelovšek, Jure Kokalj, Zala Lenarčič, Ross H. McKenzie. 2015-12-22. Holon-Doublon Binding as the Mechanism for the Mott transition. https://doi.org/10.1103/physrevb.92.235155

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