Planarized Ordered Uniform Mesa-top Single Quantum Dot Single Photon Source Arrays: A Platform for Scalable Quantum Optical Networks*

Realization of on-chip scalable optical networks demand ordered and spectrally uniform single photon source (SPS) array. To this end, we have demonstrated such SPSs based on a new class of spatially ordered and spectrally uniform InGaAs/GaAs single quantum dots (SQDs) that reside on nanomesa tops [1,2]. Here we report on binary InAs/GaAs mesa-top SQDs (MTSQDs) in 5×8 arrays exhibiting unprecedented emission nonuniformity of 1.8nm (<2meV) over 1000um² area with, strikingly, up to 49 pairs and even 2 sets of 6-7 MTSQDs emitting within 0.2nm (280μeV), ready for on-chip tuning to be brought on resonance[3]. These InAs MTSQDs exhibit single photon emission purity >99.5% (g⁽²⁾(0)<0.01)[3]. To enable use in optical circuits, the nanomesa array morphology needs to be planarized and we report here the growth protocol for GaAs overlayer that planarizes the MTSQDs and maintains MTSQDs uniformity and single photon emission purity [3]. Such planarized SQD SPS arrays in a GaAs matrix provide the much-awaited platform for realizing quantum optical circuits. Work on integration is underway.
[1] J.Zhang et.al,J.Appl.Phys.120,243103(2016)
[2] J.Zhang et.al,Appl.Phys.Lett.114,071102(2019)
[3] J. Zhang et.al,APL Photonics(2020) (in press)