Nanowire Quantum Dots
Deterministic site control of quantum dots (QDs) has many potential benefits, including the enhancement of photoluminescence coupling to photonic cavities and easing multi-qubit scale-up for quantum information applications. Since standard Stranski-Krastanow growth is incompatible with this goal, other approaches must be considered. At Sheffield, we are investigating the fabrication of QDs in nanowires grown by selective-area, catalyst-free MOVPE. Our current focus is on InGaAs QDs formed within GaAs nanowires, a system which has thus far produced QDs with an ensemble broadening of ~15meV, comparing favourably with similar reports in the literature.
|Academic Staff:||Luke Wilson|
|Post-Docs:||Maxim Makhonin Benjamin Royall|
|PhD Students:||Andrew Foster
Figure 1: (a) Schematic of nanowire array, highlighting position of quantum dot. (b) 45° tilted SEM of sample array with ~95% successful nanowire formation. (c) Power dependent micro-photoluminescence from nanowire quantum dot, exhibiting state filling with increasing power. The S, P and D states are labelled. (d) Micro-PL of exciton (X) and biexciton (2X) lines, revealing exciton linewidth of ~225μeV. (Inset) Result of second order auto correlation measurement, demonstrating a g(2)(t=0) value of ~50%. The emission for this measurement had a contribution from the biexciton as well as the excitonic line.