Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Weakly-coupled Hubbard chains at half-filling and Confinement   We study two (very) weakly-coupled Hubbard chains in the half-filled case,
and especially the situation where the intrachain Mott scale $m$ is much larger
than the bare single-electron interchain hopping $t_{\perp}$. First, we find
that the divergence of the intrachain Umklapp channel at the Mott transition
results in the complete vanishing of the single-electron interchain hopping:
This is significant of a strong confinement of coherence along the chains.
Excitations are usual charge fermionic solitons and spinon pairs of the
Heisenberg chain. Then, we show rigorously how the tunneling of spinon-pairs
produces a magnetic interchain exchange $J_{\perp}={t_{\perp}}^2/m>0$. The
result is an insulating state with spin-gapped excitations as in the
delocalized limit (i.e. for rather large interchain hoppings), where the
two-leg ladder is in the well-known D-Mott phase. Unlike for Bechgaard salts,
the confinement/deconfinement transition at absolute zero is here a simple
crossover: no metallic phase is found in undoped two-leg ladders. This
statement might be generalized for N-leg ladders with N=3,4... (but not too
large).

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The categories of this paper are: econ
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The categories of this paper are: alg-geom
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The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an
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The categories of this paper are: atom-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: patt-sol
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The categories of this paper are: cs
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: chao-dyn
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
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The categories of this paper are: acc-phys