Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Measurements of a quantum bulk acoustic resonator using a
  superconducting qubit   Phonon modes at microwave frequencies can be cooled to their quantum ground
state using conventional cryogenic refrigeration, providing a convenient way to
study and manipulate quantum states at the single phonon level. Phonons are of
particular interest because mechanical deformations can mediate interactions
with a wide range of different quantum systems, including solid-state defects,
superconducting qubits, as well as optical photons when using
optomechanically-active constructs. Phonons thus hold promise for
quantum-focused applications as diverse as sensing, information processing, and
communication. Here, we describe a piezoelectric quantum bulk acoustic
resonator (QBAR) with a 4.88 GHz resonant frequency that at cryogenic
temperatures displays large electromechanical coupling strength combined with a
high intrinsic mechanical quality factor $Q_i \approx 4.3 \times 10^4$. Using a
recently-developed flip-chip technique, we couple this QBAR resonator to a
superconducting qubit on a separate die and demonstrate quantum control of the
mechanics in the coupled system. This approach promises a facile and flexible
experimental approach to quantum acoustics and hybrid quantum systems.

8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg