Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Low Energy Effective Action of Lightly Doped Two-Leg t-J Ladders   We propose a low energy effective theory of lightly doped two-leg t-J ladders
with the help of slave fermion technique. The continuum limit of this model
consists of two kinds of Dirac fermions which are coupled to the O(3)
non-linear sigma model in terms of the gauge coupling with opposite sign of
"charges". In addition to the gauge interaction, there is another kind of
attractive force between these Dirac fermions, which arises from the
short-ranged antiferromagnetic order. We show that the latter is essential to
determine the low energy properties of lightly doped two-leg t-J ladders. The
effective Hamiltonian we obtain is a bosonic Gaussian model and the boson field
basically describes the particle density fluctuation. We also find two types of
gapped spin excitations. Finally, we discuss the possible instabilities: charge
density wave (CDW) and singlet superconductivity (SC). We find that the SC
instability dominates in our approximation. Our results indicate that lightly
doped ladders fall into the universality class of Luther-Emery model.

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The categories of this paper are: chem-ph
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The categories of this paper are: nlin
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The categories of this paper are: hep-ph
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The categories of this paper are: q-bio
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The categories of this paper are: math
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The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
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The categories of this paper are: physics
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The categories of this paper are: cmp-lg
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-th
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The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
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The categories of this paper are: math-ph
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The categories of this paper are: hep-ex