  Manipulation of solid-state spin coherence is an important paradigm for
quantum information processing. Current systems either operate at very low
temperatures or are difficult to scale-up. Developing low-cost, scalable
materials whose spins can be coherently manipulated at room temperature is thus
highly-attractive for a sustainable future of quantum information science. Here
we report ambient-condition all-optical initialization, manipulation and
readout of single-hole spins in an ensemble of solution-grown CsPbBr3
perovskite QDs. Single-hole spins are obtained by sub-picosecond electron
scavenging following a circularly-polarized femtosecond-pulse excitation. A
transversal magnetic field induces spin precession, and a second off-resonance
femtosecond-pulse coherently rotates hole spins via strong light-matter
interaction. These operations accomplish nearly complete quantum-state control
of single-hole spins at room temperature.
