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arXiv · 0811.0590

Spontaneous Currents in Spinless Fermion Lattice Models at the Strong-Coupling Limit

Sumiran Pujari·C. L. Henley
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Abstract

What kind of lattice Hamiltonian manifestly has an ordered state with spontaneous orbital currents? We consider interacting spinless fermions on an array of square plaquettes, connected by weak hopping; the array geometry may be a 2 x 2L ladder, a 2 x 2 x 2L "tube", or a 2L x 2L square grid. At half filling, we derive an effective Hamiltonian in terms of pseudospins, of which one component represents orbital currents, and find the conditions sufficient for orbital current long-range order. We consider spinfull variants of the aforesaid spinless models and make contact with other spinfull models in the literature purported to possess spontaneous currents.

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Sumiran Pujari, C. L. Henley. 2008-11-04. Spontaneous Currents in Spinless Fermion Lattice Models at the Strong-Coupling Limit. https://doi.org/10.1103/physrevb.80.085116

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