Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quasiparticle interference on the surface of 3D topological insulator
  Bi$_{2}$Se$_{3}$ induced by cobalt adatom in the absence of ferromagnetic
  ordering   Quasiparticle interference induced by cobalt adatoms on the surface of the
topological insulator Bi$_{2}$Se$_{3}$ is studied by scanning tunneling
microscopy, angle-resolved photoemission spectroscopy and X-ray magnetic
circular dichroism. It is found that Co atoms are selectively adsorbed on top
of Se sites and act as strong scatterers at the surface, generating anisotropic
standing waves. A long-range magnetic order is found to be absent, and the
surface state Dirac cone remains gapless. The anisotropy of the standing wave
is ascribed to the heavily warped iso-energy contour of unoccupied states,
where the scattering is allowed due to a non-zero out-of-plane spin.

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The categories of this paper are: astro-ph
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The categories of this paper are: stat
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The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
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The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: hep-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph