Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Characterization of Er$^{3+}$:YVO$_{4}$ for microwave to optical
  transduction   Quantum transduction between microwave and optical frequencies is important
for connecting superconducting quantum platforms in a quantum network.
Ensembles of rare-earth ions are promising candidates to achieve this
conversion due to their collective coherent properties at microwave and optical
frequencies. Erbium ions are of particular interest because of their telecom
wavelength optical transitions that are compatible with fiber communication
networks. Here, we report the optical and electron spin properties of erbium
doped yttrium orthovanadate (Er$^{3+}$:YVO$_{4}$), including high-resolution
optical spectroscopy, electron paramagnetic resonance studies and an initial
demonstration of microwave to optical conversion of classical fields. The
highly absorptive optical transitions and narrow ensemble linewidths make
Er$^{3+}$:YVO$_{4}$ promising for magneto-optic quantum transduction.

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The categories of this paper are: plasm-ph
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an