  Connecting two half-filled quantum dots to two superconducting leads induces
a competition of bonds, with the dots forming either an interdot exchange bond
or two individual Yu-Shiba-Rusinov (YSR) screening bonds with the leads.
Defining a qubit using these singlet parity bonding states provides dot charge
noise protection, attributed to the chargeless nature of the screening
quasiparticles, and magnetic noise protection, as the bonds guard against
magnetic polarization. In this paper, we propose embedding a Double Quantum Dot
(DQD) Josephson junction in parallel with a transmon to enable circuit Quantum
Electrodynamics (cQED) measurements and operation of a YSR bond qubit. We
demonstrate that, under realistic parameters, two-tone spectroscopy of the DQD
can be performed, revealing a significant parameter regime suitable for qubit
operation. Additionally, coherent manipulations of the bond states can be
achieved through dot gates, and single-shot readout is enabled by measurements
of a capacitively coupled resonator. Finally, we analyze noise sources and
estimate gate noise on couplings as the primary source of qubit decoherence.
Since this qubit is protected against nuclear Overhauser fields and does not
rely on spin-orbit interactions for operation, a broader range of material
platforms becomes available compared to current Andreev spin qubits.
