Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Soft-clamped silicon nitride string resonators at millikelvin
  temperatures   We demonstrate that soft-clamped silicon nitride strings with large aspect
ratio can be operated at \si{\milli\kelvin} temperatures. The quality factors
($Q$) of two measured devices show consistent dependency on the cryostat
temperature, with soft-clamped mechanical modes reaching $Q > 10^9$ at
$80~\mathrm{mK}$. For low optical readout power, $Q$ is found to saturate,
indicating good thermalization between the sample and the stage it is mounted
on. Our best device exhibits a force sensitivity of
$12.6~\mathrm{zN}/\sqrt{\mathrm{Hz}}$ and a thermal decoherence time of
$0.22~\mathrm{s}$ which bode well for future applications such as
nanomechanical force sensing and beyond.

30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat