Scalable tuning of InAs quantum dots embedded in photonic structures

The prospect of integrated quantum optics platforms based on semiconductor quantum dots (QDs) has driven quantum semiconductor research for decades. This has resulted in advanced demonstrations of single photon emission and switching, quantum transistors, and qubit-photon interfaces. However, the variation in QD emission energies – which prevents interfacing QDs with each other and photonic elements such as cavities and waveguides – has thus far limited these demonstrations to one or two QDs. We have developed an approach that addresses this challenge by laser-patterning strain via local phase transitions of a conformal thin film deposited on the surface of photonic architectures.¹ Using this approach, InAs QDs can be tuned across the entire inhomogeneous distribution, with a spectral resolution down to the homogeneous linewidth, and sub-micron spatial resolution. We show that a scalable number of QDs embedded in the same bridge waveguide can be tuned into resonance. We also demonstrate that the emission energies of QDs embedded in photonic crystal cavities and waveguides can be tuned with this approach.

1. Grim, J. Q. et al. Scalable in operando strain tuning of multiple quantum dots within a photonic waveguide architecture. arXiv: 1810.05195 [quant-ph] 1–19 (2018).