Strong Correlation, Bloch Bundle Topology and Spinless Haldane-Hubbard Model

Different realizations of the Hubbard operators in different Hilbert spaces give rise to various microscopic lattice electron models driven by strong correlations. In terms of the Gutzwiller projected operators, the most familiar examples are the t-J and the BCS-Hubbard models at strong coupling. We focus on the spin-dopon representation of the Hubbard operators. In this case the no double occupancy constraint (NDO) can be reexpressed as a Kondo interaction. As an explicit example, the effective low energy action is derived in terms of itinerant spineless fermions (dopons) strongly interacting with localized lattice spins.The spontaneous breaking of time reversal symmetry describes a spinless version of the Haldane-Hubbard topological theory. Our consideration suggests that the topologically non-trivial U(1) Bloch bundle associated with this model can be realized dynamically due to the presence of strong correlations even in the absence of any external flux.

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