Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Field Dependence of the Superconducting Basal Plane Anisotropy of
  TmNi2B2C   The superconductor TmNi2B2C possesses a significant four-fold basal plane
anisotropy, leading to a square Vortex Lattice (VL) at intermediate fields.
However, unlike other members of the borocarbide superconductors, the
anisotropy in TmNi2B2C appears to decrease with increasing field, evident by a
reentrance of the square VL phase. We have used Small Angle Neutron Scattering
measurements of the VL to study the field dependence of the anisotropy. Our
results provide a direct, quantitative measurement of the decreasing
anisotropy. We attribute this reduction of the basal plane anisotropy to the
strong Pauli paramagnetic effects observed in TmNi2B2C and the resulting
expansion of vortex cores near Hc2.

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The categories of this paper are: funct-an
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The categories of this paper are: q-fin
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The categories of this paper are: acc-phys
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The categories of this paper are: gr-qc
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The categories of this paper are: nlin
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The categories of this paper are: hep-ph
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The categories of this paper are: math-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: q-bio
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The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: dg-ga