Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum Impurity Problems in Condensed Matter Physics   Impurities are ubiquitous in condensed matter. Boundary Conformal Field
Theory (BCFT) provides a powerful method to study a localized quantum impurity
interacting with a gapless continuum of excitations. The results can also be
implied to nanoscopic devices like quantum dots. In these lecture notes, I
review this field, including the following topics: I. General Renormalization
Group (RG) framework for quantum impurity problems: example of simplest Kondo
model II. Multi-channel Kondo model III. Quantum Dots: experimental
realizations of one and two channel Kondo models IV. Impurities in Luttinger
liquids: point contact in a quantum wire V. Quantum impurity entanglement
entropy VI. Y-junctions of Luttinger liquids VII. Boundary condition changing
operators and the X-ray edge problem.

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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
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The categories of this paper are: nlin
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The categories of this paper are: adap-org
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The categories of this paper are: eess
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-th
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The categories of this paper are: q-alg
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat