Single SiGe Quantum Dot Emission Deterministically Enhanced in a High-Q Photonic Crystal Resonator

TL;DR

This paper demonstrates the deterministic embedding of a single SiGe quantum dot into a high-Q photonic crystal resonator, achieving record quality factors and potential for telecom photon sources.

Contribution

The authors developed a scalable MBE growth method for precise placement of a single QD in a high-Q PhCR, achieving record quality factors and detailed analysis of emission properties.

Findings

Achieved Q factors up to 10^5 for QD-loaded PhCRs.

Confirmed single QD as a potential telecom photon source.

Analyzed emission dependence on temperature, excitation, and decay.

Abstract

We report the resonantly enhanced radiative emission from a single SiGe quantum dot (QD), which is deterministically embedded into a bichromatic photonic crystal resonator (PhCR) at the position of its largest modal electric field by a scalable method. By optimizing our molecular beam epitaxy (MBE) growth technique, we were able to reduce the amount of Ge within the whole resonator to obtain an absolute minimum of exactly one QD, accurately positioned by lithographic methods relative to the PhCR, and an otherwise flat, a few monolayer thin, Ge wetting layer (WL). With this method, record quality (Q) factors for QD-loaded PhCRs up to $Q\sim 10^5$ are achieved. A comparison with control PhCRs on samples containing a WL but no QDs is presented, as well as a detailed analysis of the dependence of the resonator-coupled emission on temperature, excitation intensity, and emission decay after pulsed excitation. Our findings undoubtedly confirm a single QD in the center of the resonator as a potentially novel photon source in the telecom spectral range.