Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Quantum transduction of optical photons from a superconducting qubit   Bidirectional conversion of electrical and optical signals lies at the
foundation of the global internet. Such converters are employed at repeater
stations to extend the reach of long-haul fiber optic communication systems and
within data centers to exchange high-speed optical signals between computers.
Likewise, coherent microwave-to-optical conversion of single photons would
enable the exchange of quantum states between remotely connected
superconducting quantum processors, a promising quantum computing hardware
platform. Despite the prospects of quantum networking, maintaining the fragile
quantum state in such a conversion process with superconducting qubits has
remained elusive. Here we demonstrate the conversion of a microwave-frequency
excitation of a superconducting transmon qubit into an optical photon. We
achieve this using an intermediary nanomechanical resonator which converts the
electrical excitation of the qubit into a single phonon by means of a
piezoelectric interaction, and subsequently converts the phonon to an optical
photon via radiation pressure. We demonstrate optical photon generation from
the qubit with a signal-to-noise greater than unity by recording quantum Rabi
oscillations of the qubit through single-photon detection of the emitted light
over an optical fiber. With proposed improvements in the device and external
measurement set-up, such quantum transducers may lead to practical devices
capable of realizing new hybrid quantum networks, and ultimately, distributed
quantum computers.

27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci