Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectroscopy and Thermometry of Drumhead Modes in a Mesoscopic
  Trapped-Ion Crystal using Entanglement   We demonstrate spectroscopy and thermometry of individual motional modes in a
mesoscopic 2D ion array using entanglement-induced decoherence as a method of
transduction. Our system is a $\sim$400 $\mu$m-diameter planar crystal of
several hundred $^9$Be$^+$ ions exhibiting complex drumhead modes in the
confining potential of a Penning trap. Exploiting precise control over the
$^9$Be$^+$ valence electron spins, we apply a homogeneous spin-dependent
optical dipole force to excite arbitrary transverse modes with an effective
wavelength approaching the interparticle spacing ($\sim$20 \nolinebreak$\mu$m).
Center-of-mass displacements below 1 nm are detected via entanglement of spin
and motional degrees of freedom.

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The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
12
The categories of this paper are: nucl-th
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The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat