Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

CMP Seminar - The Growth of InP Nanowires for Quantum Light Sources

P.J. Poole
National Research Council Canada

Date: Thursday, September 24th, 2015
Time: 10:30 am
Location: Stirling 401


The growth of semiconductor nanowires has rapidly advanced in recent years to the point where it is possible to grow high purity, single crystal phase structures. The combination of their small dimensions and excellent optical waveguiding properties make them ideal candidates for quantum light sources to be used in quantum computing and quantum cryptography.

In this talk I will describe the growth of position and diameter controlled wurtzite InP nanowires using Chemical Beam Epitaxy (CBE), and demonstrate their excellent optical properties. Strong waveguiding effects were brought into play through the control of the nanowire diameter, resulting in efficient emission of photons into the fundamental waveguide mode of the nanowire. This resulted in photon collection efficiencies into a single mode fibre approaching 100%. By incorporating single InAsP quantum dots in the InP nanowire core a high brightness single photon source was demonstrated. Extremely clean single dot spectra were measured due to the lack of competing stacking fault/zincblende emission, or emission from planar substrate growth due to the selective area nature of the growth process. This source exhibited line widths as narrow as 3 μeV, probabilities of multiphoton emission g2(0)<0.005, count rates as high as 320,000 counts/s, and entangled biexciton/exciton emission.