Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum phase transitions in the systems of parallel quantum dots   We study the low-temperature transport properties of the systems of parallel
quantum dots described by the N-impurity Anderson model. We calculate the
quasiparticle scattering phase shifts, spectral functions and correlations as a
function of the gate voltage for N up to 5. For any N, the conductance at the
particle-hole symmetric point is unitary. For N >= 2, a transition from
ferromagnetic to antiferromagnetic impurity spin correlations occurs at some
gate voltage. For N >= 3, there is an additional transition due to an abrupt
change in average impurity occupancy. For odd N, the conductance is
discontinuous through both quantum phase transitions, while for even N only the
magnetic transition affects the conductance. Similar effects should be
experimentally observable in the systems of quantum dots with ferromagnetic
conduction-band-mediated inter-dot exchange interactions.

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The categories of this paper are: astro-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: nucl-ex
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The categories of this paper are: funct-an
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The categories of this paper are: stat
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The categories of this paper are: physics
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: chem-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: econ
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The categories of this paper are: dg-ga