Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A High-Resolution Combined Scanning Laser- and Widefield Polarizing
  Microscope for Imaging at Temperatures from 4 K to 300 K   Polarized light microscopy, as a contrast-enhancing technique for optically
anisotropic materials, is a method well suited for the investigation of a wide
variety of effects in solid-state physics, as for example birefringence in
crystals or the magneto-optical Kerr effect (MOKE). We present a microscopy
setup that combines a widefield microscope and a confocal scanning laser
microscope with polarization-sensitive detectors. By using a high numerical
aperture objective, a spatial resolution of about 240 nm at a wavelength of 405
nm is achieved. The sample is mounted on a $^4$He continuous flow cryostat
providing a temperature range between 4 K and 300 K, and electromagnets are
used to apply magnetic fields of up to 800 mT with variable in-plane
orientation and 20 mT with out-of-plane orientation. Typical applications of
the polarizing microscope are the imaging of the in-plane and out-of-plane
magnetization via the longitudinal and polar MOKE, imaging of magnetic flux
structures in superconductors covered with a magneto-optical indicator film via
Faraday effect or imaging of structural features, such as twin-walls in
tetragonal SrTiO$_3$. The scanning laser microscope furthermore offers the
possibility to gain local information on electric transport properties of a
sample by detecting the beam-induced voltage change across a current-biased
sample. This combination of magnetic, structural and electric imaging
capabilities makes the microscope a viable tool for research in the fields of
oxide electronics, spintronics, magnetism and superconductivity.

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The categories of this paper are: nucl-th
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
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The categories of this paper are: hep-ex
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The categories of this paper are: funct-an
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The categories of this paper are: astro-ph