Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Near-Room-Temperature Valence Transition in a Strain-Tuned Perovskite
  Oxide   Cobalt oxides have long been understood to display intriguing phenomena known
as spin-state crossovers, where the cobalt ion spin changes vs. temperature,
pressure, etc. A very different situation was recently uncovered in some
praseodymium-containing cobalt oxides, where a first-order coupled
spin-state/structural/metal-insulator transition occurs, driven by a remarkable
praseodymium valence transition. Such valence transitions, particularly when
triggering spin-state and metal-insulator transitions, offer highly appealing
functionality, but have thus far been confined to cryogenic temperatures in
bulk materials. Here, we show that in thin films of the perovskite
(Pr1-yYy)1-xCaxCoO3-{\delta}, heteroepitaxial strain tuning enables
stabilization of valence-driven spin-state/structural/metal-insulator
transitions to at least 245 K, potentially within reach of room temperature.
The technological implications of this result are accompanied by fundamental
prospects also, as complete strain control of the electronic ground state is
demonstrated, from ferromagnetic metal under tension to nonmagnetic insulator
under compression, potentially exposing a novel quantum critical point.

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The categories of this paper are: solv-int
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The categories of this paper are: cmp-lg
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The categories of this paper are: q-fin
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The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
6
The categories of this paper are: astro-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: stat
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-ex
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The categories of this paper are: physics
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg