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arXiv · 0802.3880

Doped AB_2 Hubbard Chain: Spiral, Nagaoka and RVB States, Phase Separation and Luttinger Liquid Behavior

R. R. Montenegro-Filho·M. D. Coutinho-Filho
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Abstract

We present an extensive numerical study of the Hubbard model on the doped AB$_2$ chain, both in the weak coupling and the infinite-U limit. Due to the special unit cell topology, this system displays a rich variety of phases as function of hole doping ($δ$) away from half-filling. Near half-filling, spiral states develop in the weak coupling regime, while Nagaoka itinerant ferromagnetism is observed in the infinite-U limit. For higher doping the system phase-separates before reaching a Mott insulating phase of short-range RVB states at $δ=1/3$. Moreover, for $δ>1/3$ we observe a crossover, which anticipates the Luttinger liquid behavior for $δ> 2/3$.

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R. R. Montenegro-Filho, M. D. Coutinho-Filho. 2008-02-26. Doped AB_2 Hubbard Chain: Spiral, Nagaoka and RVB States, Phase Separation and Luttinger Liquid Behavior. https://doi.org/10.1103/physrevb.74.125117

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