Phys.org July 25, 2023
Coherently driven semiconductor quantum dots are one of the most promising platforms for non-classical light sources and quantum logic gate. However, 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. An international team of researchers (UK, Germany, China) demonstrated an all-optical method to control high-orbital states of a hole via a stimulated Auger process. The coherent nature of the Auger process was proved by Rabi oscillation and Ramsey interference. Harnessing this coherence further enabled the investigation of the single-hole relaxation mechanism. A hole relaxation time of 161 ps was observed and attributed to the phonon bottleneck effect. According to the researchers their work opens new possibilities for understanding the fundamental properties of high-orbital states in quantum emitters and for developing new types of orbital-based quantum photonic devices… read more. TECHNICAL ARTICLE