Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Experimental realization of smectic phase in vortex matter induced by
  symmetric potentials arranged in two-fold symmetry arrays   Smectic order has been generated in superconducting Nb films with two-fold
symmetry arrays of symmetric pinning centers. Magnetic fields applied
perpendicularly to the films develop a vortex matter smectic phase that is
easily detected when the vortices commensurate with the pinning center array.
The smectic phase can be turned on and off with external parameters.

17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
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The categories of this paper are: solv-int
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
12
The categories of this paper are: nucl-th