Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: PT-Symmetric Phonon Laser   By exploiting recent developments associated with coupled microcavities, we
introduce the concept of PT-symmetric phonon laser with balanced gain and loss.
This is accomplished by introducing gain to one of the microcavities such that
it balances the passive loss of the other. In the vicinity of the gain-loss
balance, a strong nonlinear relation emerges between the intracavity photon
intensity and the input power. This then leads to a giant enhancement of both
optical pressure and mechanical gain, resulting in a highly efficient
phonon-lasing action. These results provide a promising approach for
manipulating optomechanical systems through PT-symmetric concepts. Potential
applications range from enhancing mechanical cooling to designing phonon-laser
amplifiers.

37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
2
The categories of this paper are: math