Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A self-stabilized coherent phonon source driven by optical forces   Optical forces can set tiny objects into states of coherent mechanical
oscillation, also known as mechanical or phonon lasing. We present a novel
pumping mechanism in an opto-mechanical photonic crystal that realizes
mechanical lasing with relaxed requirements for the optical-mechanical modes
and their inter-coupling. It derives from a spontaneously triggered
thermal/free carrier self-pulsing and the anharmonic modulation of the
radiation pressure force that comes as a consequence. Moreover, the feedback of
the mechanics on the self-pulsing frequency-entrains both oscillators, creating
a self-stabilized indecomposable system. A manifold of frequency-entrained
regions with two different mechanical modes (at 54 and 122 MHz) are observed as
a result of the wide tuneability of the natural frequency of the self-pulsing.
The system operates at ambient conditions of pressure and temperature in a
silicon compatible platform, which enables its exploitation in sensing,
intra-chip metrology or time-keeping applications.

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The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph