  Quantum phase-slip (QPS) is the exact dual to the well-known Josephson
effect. Although there are numerous proposals for applications of QPS devices,
experimental work to develop these remains in the relatively early stages.
Significant barriers to exploiting QPS nanowires for useful technologies still
exist, such as establishing robust nanowire fabrication methods that allow
coupling to low-loss circuits, and demonstrating control over the QPS process
with an experimenter-controlled external bias. Here we report experiments which
show that both of these barriers have been overcome. We present measurements at
300 mK of NbN coplanar waveguide (CPW) resonators embedded with nanowires
fabricated using a neon focused ion-beam. The internal quality factor exceeds
$2\times10^{4}$ -- significantly higher than previously reported in comparable
experiments. The resonator frequency tunes periodically with an applied
magnetic field, revealing tunnelling of the order parameter that always occurs
at half-integer values of the applied flux. In contrast to previous studies of
single QPS, the order-parameter tunnelling is shown to be adiabatic,
demonstrating improved control over energy dissipation in nanowire QPS
circuits. Our results highlight a promising pathway towards realising low-loss
nanowire-based QPS devices.
