Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High-frequency traveling-wave phononic cavity with sub-micron wavelength   Thin-film gallium nitride (GaN) as a proven piezoelectric material is a
promising platform for the phononic integrated circuits, which hold great
potential for scalable information processing processors. Here, an unsuspended
traveling phononic resonator based on high-acoustic-index-contrast mechanism is
realized in GaN-on-Sapphire with a frequency up to 5 GHz, which matches the
typical superconducting qubit frequency. A sixfold increment in quality factor
was found when temperature decreases from room temperature ($Q=5000$) to
$7\,\mathrm{K}$ ($Q=30000$) and thus a frequency-quality factor product of
$1.5\times10^{14}$ is obtained. Higher quality factors are available when the
fabrication process is further optimized. Our system shows great potential in
hybrid quantum devices via circuit quantum acoustodynamics.

15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math