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Spinless fermions ladders at half filling

P. Donohue·M. Tsuchiizu·T. Giamarchi·Y. Suzumura
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Abstract

We study a half filled ladder of spinless fermions. We show that contrarily to a single chain, the ladder becomes a Mott insulator for arbitrarily small repulsive interactions. We obtain the full phase diagram and physical quantities such as the charge gap. We show that there is only a single insulating phase for repulsive interactions, regardless of the stength of the interchain hopping and single chain Mott gap. There is thus no confinement-deconfinement transition in this system but a simple crossover. We show that upon doping the system becomes a Luttinger liquid with a universal parameter $K=1/2$ different from the one of the single chain ($K=1/4$).

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P. Donohue, M. Tsuchiizu, T. Giamarchi, Y. Suzumura. 2000-07-21. Spinless fermions ladders at half filling. https://doi.org/10.1103/physrevb.63.045121

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