Quantum communication applications require a scalable approach to integrate bright sources of entangled photon-pairs in complex on-chip quantum circuits. Currently, the most promising sources are based on III/V semiconductor quantum dots. However, complex photonic circuitry is mainly achieved in silicon photonics due to the tremendous technological challenges in circuit fabrication. We take the best of both worlds by developing a new hybrid on-chip nanofabrication approach. We demonstrate for the first time on-chip generation, spectral filtering, and routing of single-photons from selected single and multiple III/V semiconductor nanowire quantum emitters all deterministically integrated in a CMOS compatible silicon nitride photonic circuit.
Nanowires offer new opportunities for nanoscale quantum optics; the quantum dot geometry in semiconducting nanowires as well as the material composition and environment can be engineered with unprecedented freedom to improve the light extraction efficiency.
Quantum dots in nanowires are shown to be efficient single photon sources, in addition because of the very small fine structure splitting, we demonstrate the generation of entangled pairs of photons from a nanowire.
Another type of nanowire under study in our group is superconducting nanowires for single photon detection, reaching efficiencies, time resolution and dark counts beyond currently available detectors. We will discuss our first attempts at combining semiconducting nanowire based single photon emitters and superconducting nanowire single photon detectors on a chip to realize integrated quantum circuits.
Here we present a fully quantum mechanical transfer function model for travelling wave whispering gallery mode
resonators. Micro-resonators, such as ring and disk resonators, have been key to the development of high performance
chip-scale photonic systems due to their compact footprint, sensitivity and low power operation. In this work we present
the first understanding of these resonators to any arbitrary multi-photon state. This was achieved by developing a model
that utilizes an efficient scheme for determining the quantum electrodynamic transfer functions relating the Bosonic
input/output mode operators in the resonator. This approach has been applied to the understanding of both single photon
and two-photon states. In this work we will present a key result on a resonant Hong-Ou-Mandel effect that is inherently
realized for any resonator-waveguide coupling constants and can operate over a wide range of resonance conditions.
Furthermore, the transfer function approach allows for the straightforward understanding of any resonator-waveguide
network with arbitrary modes. This will directly enable the application of quantum resonators to the realization of robust,
scalable and efficient Linear Optical Quantum Computing (LOQC) gates. Consequently, it is expected that resonators
can be used for both Nonlinear Sign Shift and CNOT gates. And these gates can robustly controlled and efficiently tuned
using standard electro-optic effects available in a variety of material systems, such as, Silicon.