Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Enhancement of Superconductivity Linked with Linear-in-Temperature/Field
  Resistivity in Ion-Gated FeSe Films   Iron selenide (FeSe) - the structurally simplest iron-based superconductor,
has attracted tremendous interest in the past years. While the transition
temperature (Tc) of bulk FeSe is $\sim$ 8 K, it can be significantly enhanced
to 40 - 50 K by various ways of electron doping. However, the underlying
physics for such great enhancement of Tc and so the Cooper pairing mechanism
still remain puzzles. Here, we report a systematic study of the
superconducting- and normal-state properties of FeSe films via ionic liquid
gating. With fine tuning, Tc evolves continuously from below 10 K to above 40
K; in situ two-coil mutual inductance measurements unambiguously confirm the
gating is a uniform bulk effect. Close to Tc, the normal-state resistivity
shows a linear dependence on temperature and the linearity extends to lower
temperatures with the superconductivity suppressed by high magnetic fields. At
high fields, the normal-state magnetoresistance exhibits a linear-in-field
dependence and obeys a simple scaling relation between applied field and
temperature. Consistent behaviors are observed for different-Tc states
throughout the gating process, suggesting the pairing mechanism very likely
remains the same from low- to high-Tc state. Importantly, the coefficient of
the linear-in-temperature resistivity is positively correlated with Tc,
similarly to the observations in cuprates, Bechgaard salts and iron pnictide
superconductors. Our study points to a short-range antiferromagnetic exchange
interaction mediated pairing mechanism in FeSe.

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The categories of this paper are: math
31
The categories of this paper are: ao-sci
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
23
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: hep-th
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The categories of this paper are: atom-ph
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The categories of this paper are: nlin
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The categories of this paper are: nucl-th