Bulk AlInAs on InP(111) as a novel material system for pure single photon emission

In this letter, we report on quantum light emission from bulk AlInAs grown on InP(111) substrates. We observe indium rich clusters in the bulk Al_0.48In_0.52As (AlInAs), resulting in quantum dot-like energetic traps for charge carriers, which are confirmed via cross-sectional scanning tunnelling microscopy (XSTM) measurements and 6-band k·p simulations. We observe quantum dot (QD)-like emission signals, which appear as sharp lines in our photoluminescence spectra at near infrared wavelengths around 860 nm, and with linewidths as narrow as 50 μeV. We demonstrate the capability of this new material system to act as an emitter of pure single photons as we extract g⁽²⁾-values as low as gcw(2)(0)=0.05-0.05+0.17 for continuous wave (cw) excitation and gpulsed,  corr.(2)=0.24±0.02 for pulsed excitation.