Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Symmetrical broken and nonlinear response of Weyl semimetal TaAs
  influenced by the topological surface states and Weyl nodes   A Weyl semimetal (WSM) features Weyl fermions in its bulk and topological
surface states on surfaces, and is novel material hosting Weyl fermions, a kind
of fundamental particles. The WSM was regarded as a three-dimensional version
of "graphene" under the illusion. In order to explore its promising
photoelectric properties and applications in photonics and photoelectronics,
here, we study the anisotropic linear and nonlinear optical responses of a WSM
TaAs, which are determined by the relationship and balance between its
topological surface states and Weyl nodes. We demonstrate that topological
surface states which break the bulk symmetry are responsible for the anisotropy
of the mobility, and the anisotropic nonlinear response shows saturable
characteristic with extremely large saturable intensity. We also find that the
mobility is anisotropic with the magnitude of 104 cm2V-1s-1 at room temperature
and can be accelerated by the optical field. By analyzing the symmetry, the
nonlinear response is mainly contributed by the fermions close to the Weyl
nodes, and is related to the Pauli's blocking of fermions, electron-electron
interaction. This work experimentally discovers the anisotropic ultrahigh
mobility of WSMs in the optical field and may start the field for the
applications of WSMs in photonics and photoelectronics.

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The categories of this paper are: nucl-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: math
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The categories of this paper are: math-ph
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The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: solv-int
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The categories of this paper are: nucl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: plasm-ph
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The categories of this paper are: funct-an
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The categories of this paper are: bayes-an
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The categories of this paper are: alg-geom