Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Towards cavity-free ground state cooling of an acoustic-frequency
  silicon nitride membrane   We demonstrate feedback cooling of a millimeter-scale, 40 kHz SiN membrane
from room temperature to 5 mK (3000 phonons) using a Michelson interferometer,
and discuss the challenges to ground state cooling without an optical cavity.
This advance appears within reach of current membrane technology, positioning
it as a compelling alternative to levitated systems for quantum sensing and
fundamental weak force measurements.

29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
19
The categories of this paper are: eess
18
The categories of this paper are: econ
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th