  Coherently driven semiconductor quantum dots are one of the most promising
platforms for non-classical light sources and quantum logic gates which form
the foundation of photonic quantum technologies. However, to date, coherent
manipulation of single charge carriers in quantum dots is limited mainly to
their lowest orbital states. Ultrafast coherent control of high-orbital states
is obstructed by the demand for tunable terahertz pulses. To break this
constraint, we demonstrate an all-optical method to control high-orbital states
of a hole via stimulated Auger process. The coherent nature of the Auger
process is proved by Rabi oscillation and Ramsey interference. Harnessing this
coherence further enables the investigation of single-hole relaxation
mechanism. A hole relaxation time of 161 ps is observed and attributed to the
phonon bottleneck effect. Our work opens new possibilities for understanding
the fundamental properties of high-orbital states in quantum emitters and
developing new types of orbital-based quantum photonic devices.
