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The N-chain Hubbard Model in Weak Coupling

Hsiu-Hau Lin·Leon Balents·Matthew P. A. Fisher
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Abstract

We present a systematic weak-coupling renormalization group (RG) technique for studying a collection of $N$ coupled one-dimensional interacting electron systems, focusing on the example of N-leg Hubbard ladders. For $N=2,3$, we recover previous results, and find that also more generally broad regions of the phase space of these models are unstable to pairing, usually with approximate d-wave symmetry. We show how these instabilities can be understood in terms of a fairly conventional ``gap'' function $Δ$ at the discretized Fermi surface, and describe how this function is calculated. The dimensional crossovers as $N \to \infty$ and as many such ladders are weakly coupled together are also discussed.

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Hsiu-Hau Lin, Leon Balents, Matthew P. A. Fisher. 1998-01-31. The N-chain Hubbard Model in Weak Coupling. https://doi.org/10.1103/physrevb.56.6569

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