Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spin Chern Pumping from the Bulk of Two-Dimensional Topological
  Insulators   Topological insulators (TIs) are a new quantum state of matter discovered
recently, which are characterized by unconventional bulk topological
invariants. Proposals for practical applications of the TIs are mostly based
upon their metallic surface or edge states. Here, we report the theoretical
discovery of a bulk quantum pumping effect in a two-dimensional TI electrically
modulated in adiabatic cycles. In each cycle, an amount of spin proportional to
the sample width can be pumped into a nonmagnetic electrode, which is
attributed to nonzero spin Chern numbers $C_{\pm}$. Moreover, by using a
half-metallic electrode, universal quantized charge pumping conductivities
$-C_{\pm}e^2/h$ can be measured. This discovery paves the way for direct
investigation of the robust topological properties of the TIs.

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The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
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The categories of this paper are: supr-con
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The categories of this paper are: eess
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The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: solv-int
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an