  Holes confined in quantum dots have gained considerable interest in the past
few years due to their potential as spin qubits. Here we demonstrate double
quantum dot devices in Ge hut wires. Low temperature transport measurements
reveal Pauli spin blockade. We demonstrate electric-dipole spin resonance by
applying a radio frequency electric field to one of the electrodes defining the
double quantum dot. Next, we induce coherent hole spin oscillations by varying
the duration of the microwave burst. Rabi oscillations with frequencies
reaching 140MHz are observed. Finally, Ramsey experiments reveal dephasing
times of 130ns. The reported results emphasize the potential of Ge as a
platform for fast and scalable hole spin qubit devices.
