Deterministic nanofabrication for engineering nanowire quantum dot devices

Authors:Tarun Patel, Matteo Pennacchietti, Greg Holloway, Stephen R. Harrigan, Sayan Gangopadhyay, Anthony Drouin, Megha Jain, Dan Dalacu, Philip J. Poole, Sasan Vosoogh-Grayli, Michael E. Reimer

Abstract:Semiconductor quantum dots (QDs) are a leading platform for realising bright, wavelength-tunable sources of single and entangled photon pairs for photonic quantum technologies. Site-selected nanowire quantum dots (NWQDs) are a promising platform for fabricating such photonic devices in a scalable manner. However, implementing additional structures around the photonic nanowire while maintaining its vertical growth geometry has remained a challenge. In this work, we develop a deterministic pick-and-place technique to conduct a vertical-to-vertical transfer of NWQDs from the growth substrate to arbitrary templates. Using this transfer technique, we enhance the photon extraction efficiency to 75% by implementing a bottom gold mirror and tune the emission wavelength by 3.6 GHz via implementing electrostatic gates around the QD. Importantly, we measure low-multiphoton probability (g^(2)(0) = 0.002) and high indistinguishability (>80% for +/-100 ps) of the QD emission after the transfer process, yielding high-quality devices. These results demonstrate the repeatability and versatility of the developed transfer technique, which is an enabling step towards scalable single and entangled photon sources.

Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Quantum Physics (quant-ph)

arXiv:2609.03076 [cond-mat.mes-hall]

(or arXiv:2609.03076v1 [cond-mat.mes-hall] for this version)

https://doi.org/10.48550/arXiv.2609.03076 arXiv-issued DOI via DataCite (pending registration)