Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unidirectional valley-contrasting photo-current in strained transition
  metal dichalcogenide monolayers   We examine the static non-linear optical response of monolayer uniaxial
strained transition metal dichalcogenides. Whereas the shift current is
suppressed, we identify a strong, valley-dependent non-reciprocal response,
which we term a \textit{unidirectional valley-contrasting photo-current}
(UVCP). It originates from Kramers symmetry breaking by trigonal warping. The
UVCP is proportional to the mobility and is enhanced by the excitonic Coulomb
interaction and inter-valley scattering, enabling monitoring of inter-valley
transitions. We discuss detection strategies in state-of-the-art experiments.

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The categories of this paper are: cs
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The categories of this paper are: solv-int
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The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: comp-gas
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The categories of this paper are: eess
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The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: astro-ph