Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Superconductivity induced by electron doping in the system La1-xMxOBiS2
  (M = Ti, Zr, Hf, Th)   We report a strategy to induce superconductivity in the BiS$_2$-based
compound LaOBiS$_2$. Instead of substituting F for O, we increase the
charge-carrier density (electron dope) via substitution of tetravalent
Th$^{+4}$, Hf$^{+4}$, Zr$^{+4}$, and Ti$^{+4}$ for trivalent La$^{+3}$. It is
found that both the LaOBiS$_2$ and ThOBiS$_2$ parent compounds are bad metals
and that superconductivity is induced by electron doping with \emph{T$_c$}
values of up to 2.85 K. The superconducting and normal states were
characterized by electrical resistivity, magnetic susceptibility, and heat
capacity measurements. We also demonstrate that reducing the charge-carrier
density (hole doping) via substitution of divalent Sr$^{+2}$ for La$^{+3}$ does
not induce superconductivity.

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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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The categories of this paper are: q-fin
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The categories of this paper are: q-bio
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The categories of this paper are: cs
0
The categories of this paper are: hep-ph
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The categories of this paper are: eess
5
The categories of this paper are: gr-qc
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The categories of this paper are: stat
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The categories of this paper are: ao-sci
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The categories of this paper are: plasm-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: econ
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The categories of this paper are: nlin
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The categories of this paper are: adap-org
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The categories of this paper are: acc-phys