Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Persistence of spin edge currents in disordered quantum spin Hall
  systems   For a disordered two-dimensional model of a topological insulator (such as a
Kane-Mele model with disordered potential) with small coupling of spin
invariance breaking term (such as the Rashba coupling), it is proved that the
spin edge currents persist provided there is a spectral gap and the spin Chern
numbers are well-defined and non-trivial. These conditions on being in the
quantum spin Hall phase do not require time-reversal symmetry. The result
materializes the general philosophy that topological insulators are non-trivial
bulk systems with edge currents that are topologically protected against
Anderson localization.

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The categories of this paper are: physics
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
15
The categories of this paper are: nucl-ex
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The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys