Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Position measurement of a levitated nanoparticle via interference with
  its mirror image   Interferometric methods for detecting the motion of a levitated nanoparticle
provide a route to the quantum ground state, but such methods are currently
limited by mode mismatch between the reference beam and the dipolar field
scattered by the particle. Here we demonstrate a self-interference method to
detect the particle's motion that solves this problem. A Paul trap confines a
charged dielectric nanoparticle in high vacuum, and a mirror retro-reflects the
scattered light. We measure the particle's motion with a sensitivity of
$1.7\times 10^{-12} \text{m}/\sqrt{\text{Hz}}$, corresponding to a detection
efficiency of 2.1%, with a numerical aperture of 0.18. As an application of
this method, we cool the particle, via feedback, to temperatures below those
achieved in the same setup using a standard position measurement.

14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
6
The categories of this paper are: astro-ph