Control of single photon emitters in semiconductor nanowires by surface acoustic waves

Abstract

We report on experimental study into the effects of surface acoustic waves on the optical emission of dot-in-a-nanowire heterostructures in III-V material systems. Under direct optical excitation, the excitonic energy levels in III-nitride dot-in-ananowire heterostructures oscillate at the acoustic frequency, producing a characteristic splitting of the emission lines in the time-integrated photoluminescence spectra. This acoustically induced periodic tuning of the excitonic transition energies is combined with spectral detection filtering and employed as a tool to regulate the temporal output of anti-bunched photons emitted from these nanowire quantum dots. In addition, the acoustic transport of electrons and holes along a III-arsenide nanowire injects the electric charges into an ensemble of quantum dot-like recombination centers that are spatially separated from the optical excitation area. The acoustic population and depopulation mechanism determines the number of carrier recombination events taking place simultaneously in the ensemble, thus allowing a control of the anti-bunching degree of the emitted photons. The present results are relevant for the dynamic control of single photon emission in III-V semiconductor heterostructures.Keywords: single photon emitters, dot-in-a-nanowire heterostructures, surface acoustic waves This Accepted Manuscript is available for reuse under a CC BY-NC-ND 3.0 licence after the 12 month embargo period provided that all the terms of the licence are adhered to.

Dynamically tuned non-classical light emission from atomic defects in hexagonal boron nitride

“…Averaged over time, this modulation gives rise to an apparent splitting of the emission energies. Similar optical response to the acousto-mechanical contribution has been previously reported for quantum well 30,31 and QD 20,21,[32][33][34] heterostructures in III-V semiconductors. In this context, the observed energy splitting reflects the difference between the transition energies at phases during the acoustic cycle corresponding to maximum compressive and tensile strain (marked with E max and E min in Fig.…”

Acoustically regulated optical emission dynamics from quantum dot-like emission centers in GaN/InGaN nanowire heterostructures

“…[7,14] at a temperature of T10 K under cw optical excitation. In the spectrum measured with no SAW applied we identify signatures arising from recombination of excitonic complexes corresponding to the neutral exciton (X=1e+1h) at E0,X=2.5643 eV and biexciton (XX=2e+2h) at E0,XX=2.5871 eV [7,14]. As the IDT1 is driven at its resonance frequency of ~337.5 MHz, a large fraction of the applied rf power is transformed to the SAW.…”

“…Details on the rf characteristics of the IDTs and the SAW transmission line (in particular, the scattering parameters S11 (reflection) and S21 (transmission and insertion loss) around the resonance) are given in Ref. [7].…”

“…As in the case of lower Prf values in figure 5(a), the resulting sequential increase of the emission intensity during its decay again reflects the SAW phases at which the amplitude of FX attains its maximum value. Because the diameter of the laser spot is larger than the probed NW heterostructure hosting the QD and its energy is above the absorption edge of the InGaN section in the NW apex, the carriers are generated in the entire topmost InGaN region [7,14,15]. Since the studied QD is, in fact, a potential trap induced by indium content fluctuations within the InGaN apex [14,15], it acts as an optically active deep trap for electrons and holes photo-excited in the InGaN region (cf.…”

“…These concepts were built on schemes that have been previously established for planar semiconductor systems. Compared to all-electrical approaches, which typically require selective doping and sophisticated nanofabricated electrical contacts on individual NWs with sub-micrometer dimensions, the SAW-spectroscopy has proven to be a powerful contactless technique for: the control of acoustoelectrically induced conveyance of charge carriers and dissociated excitons across the NW [4][5][6][7], dynamic programing of NW QD occupancy state [8], precisely timed carrier injection into and extraction from NW QDs for low-jitter single photon emission [6,7], tuning of the NW QD radiative optical transitions by the oscillating strain and piezoelectric SAW fields [9,10], as well as coherent control of NW-based nanophotonic resonators [11]. Because the SAWs propagate at the speed of sound, their wavelengths in semiconductor heterostructures are typically in the micrometer and sub-micrometer range, thus covering acoustic frequencies from several tens of megahertz up to the gigahertz range.…”