Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dark States and Coherent Control of Spin States in Molecular Magnets   We propose a scheme to realize coherent control of spin states of molecule
magnet, Ni$_4$. We introduce transverse magnetic fields with special
frequencies. When the frequencies of transverse magnetic fields match in some
conditions, we obtain dark states in Ni$_4$ molecules. Through adjusting the
magnitude of magnetic fields, we can obtain any arbitrary superposition of the
two ground spin states of Ni$_4$ molecules.

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The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: funct-an
2
The categories of this paper are: math
18
The categories of this paper are: econ
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The categories of this paper are: chem-ph
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The categories of this paper are: eess
1
The categories of this paper are: cs
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
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The categories of this paper are: q-alg
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The categories of this paper are: nucl-ex
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The categories of this paper are: acc-phys
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The categories of this paper are: hep-lat