Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nodeless superconductivity in the charge density wave superconductor
  LaPt$_2$Si$_2$   We have studied the superconducting gap structure of LaPt$_2$Si$_2$ by
measuring the temperature dependence of the London penetration depth shift
$\Delta\lambda(T)$ and point contact spectroscopy of single crystals.
$\Delta\lambda(T)$ shows an exponential temperature dependence at low
temperatures, and the derived normalized superfluid density $\rho_{s}(T)$ can
be well described by a single-gap s-wave model. The point-contact conductance
spectra can also be well fitted by an s-wave Blonder-Tinkham-Klapwijk model,
where the gap value shows a typical BCS temperature and magnetic field
dependence consistent with type-II superconductivity. These results suggest
fully gapped superconductivity in LaPt$_2$Si$_2$, with moderately strong
electron-phonon coupling.

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The categories of this paper are: hep-ph
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The categories of this paper are: stat
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The categories of this paper are: adap-org
6
The categories of this paper are: astro-ph
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The categories of this paper are: eess
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The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
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The categories of this paper are: hep-th
3
The categories of this paper are: physics
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The categories of this paper are: alg-geom
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The categories of this paper are: dg-ga
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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: mtrl-th
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn