Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nanoscale polarization switching mechanisms in multiferroic BiFeO$_3$
  thin films   Ferroelectric switching in BiFeO$_3$ multiferroic thin films with intrinsic
``stripe-like'' and ``bubble-like'' polydomain configurations was studied by
piezoresponse force microscopy. Using the local electric field applied by a
scanning probe microscope tip, we observe reversal of both out-of-plane and
in-plane components of the polarization, with the final domain state depending
on the tip sweeping direction. In ``bubble-like'' samples, complete control of
the polarization is achieved, with in-plane polarization change mediated and
stabilized by out-of-plane polarization reversal. In ``stripe-like'' samples
the intrinsic domain structure influences polarization switching and in-plane
reversal may occur without out-of-plane change. The observed switching
behaviour can be well correlated with the radial and vertical components of the
highly inhomogeneous electric field applied by the tip.

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The categories of this paper are: alg-geom
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The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th
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The categories of this paper are: econ
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The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
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The categories of this paper are: eess
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The categories of this paper are: q-fin
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The categories of this paper are: chem-ph
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The categories of this paper are: funct-an
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The categories of this paper are: nucl-th
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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: solv-int
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The categories of this paper are: stat