Correlated Structural/Chemical and Optical Characterization of Scalable, Spatially Ordered, On-Demand Single Photon Emitter Arrays

Mesa-top single quantum dots (MTSQDs) hold high promise as a suitable single photon source (SPS) platform for realization of on-chip quantum photonic circuits as they have been shown to satisfy the single photon figures of metric (high brightness, near-unity single photon purity and indistinguishability) and the system-level requirements (spatial ordering, spectral uniformity, scalability and horizontal integrability) needed for creating such circuits [1]. In this talk we present our work on establishing the scalability of InGaAs/GaAs MTSQD arrays and report on the correlated characterization of structural/chemical and optical properties of MTSQDs in small, (5x8), and large, up to (100x100), arrays through scanning transmission electron microscopy (STEM) and photoluminescence (PL) measurements. We find that the MTSQD arrays exhibit: (i) high yield of emitters with highly accurate spatial positioning (<5nm), (ii) spectrally uniform emission (σ_λ<~4nm), (iii) MTSQDs with uniform size (base lengths~20nm – 30nm, heights~4nm), shape and composition, and (iv) MTSQDs with large oscillator strengths (f_MTSQD> 25). Our results show that scaling to large arrays retains the unique characteristics of MTSQDs which underpins their suitability for realization of on-chip quantum photonic circuits.