Deterministic, dynamically reconfigurable single quantum emitters enabled by tip-enhanced nano-optical trapping...

Nanocavity optical trapping has enabled the isolation and precise positioning of nanoscale objects, from single molecules to quantum emitters. Yet, practically deployable single quantum sources require more than trapping, i.e., they require real-time control over position, polarization, brightness, and wavelength. Achieving such dynamic modulation remains a critical challenge, but is key to realizing ultra-secure quantum communication and adaptive quantum sensing. Here, we present tip-enhanced nano-optical trapping spectroscopy, utilizing shear-force atomic force microscopy in liquid, to achieve deterministic and dynamically reconfigurable single quantum emitters. This approach enables precise positioning and dipole alignment of cavity-coupled single quantum dots (QDs), driven by nano-optical gradient forces and field-induced torque, with simultaneous nano-spectroscopic analysis. Moreover, dynamic control of the tip-cavity mode volume and tip-induced pressure allows further tuning of trapping and coupling behaviors, modulating the quantum emission characteristics, e.g., brightness and photon energy, from the weak to the strong coupling regime. This work represents a significant advancement toward realizing the vast potential of QDs in quantum applications, such as tuning emission properties of single photon sources for quantum switches and modulators, or implementing quantum gates via plexciton state manipulation.