  A controlled qubit in a rotating frame opens new opportunities to probe
fundamental quantum physics, such as geometric phases in physically rotating
frames, and can potentially enhance detection of magnetic fields. Realising a
single qubit that can be measured and controlled during physical rotation is
experimentally challenging. In this work, we demonstrate quantum control of a
single nitrogen-vacancy (NV) centre within a diamond rotated at 200,000rpm, a
rotational period comparable to the NV spin coherence time $T_2$. We
stroboscopically image individual NV centres that execute rapid circular motion
in addition to rotation, and demonstrate preparation, control and readout of
the qubit quantum state with lasers and microwaves. Using spin-echo
interferometry of the rotating qubit, we are able to detect modulation of the
NV Zeeman shift arising from the rotating NV axis and an external DC magnetic
field. Our work establishes single NV qubits in diamond as quantum sensors in
the physically rotating frame, and paves the way for the realisation of
single-qubit diamond-based rotation sensors.
