Semiconductor quantum nano-photonics

Lead Research Organisation: University of Sheffield
Department Name: Physics and Astronomy

Abstract

- Brief description of the context of the research including potential impact
This PhD will involve the study of quantum nano-photonic systems consisting of semiconductor quantum dots (QDs) embedded in on-chip waveguides. Strong, near deterministic, interactions between photons in the waveguides and the QD 2-level system give rise to strong non-linearities that can be harnessed for quantum logic. The system is scalable, allowing the investigation of entanglement generation by bringing several QDs onto resonance through a combination of local strain tuning and electric field tuning of the QD energy levels. Success in these areas would represent a major step forward in quantum information science, providing a route to on-chip quantum networks.
- Aims and objectives
Carry out the first waveguide QED studies for a single QD in a nano-photonic waveguide using short optical pulses to provide detailed time-resolved information.
Use HfO coated waveguides with laser-induced crystallisation to locally strain the QDs in both nanobeam and photonic crystal waveguides. Determine optimum exposure conditions to achieve controllable shifts.
Carry out studies of entanglement generation in waveguides with 2 or more QDs tuned into resonance using strain plus electric-field tuning.
Investigate the operation of more sophisticated nano-photonic systems, incorporating on-chip Mach Zehnder interferometers, for use as quantum phase gates.
- The research methodology, including new knowledge or techniques in engineering and physical sciences that will be investigated
Requires a combination of state-of-the-art device fabrication using electron beam lithography, atomic layer deposition of HfO and quantum optics using narrowband/ pulsed laser excitation with ultrasensitive detection. All equipment is in-place but new techniques will be developed in pulsed excitation and strain tuning using HfO, with new knowledge coming from all studies.
- Alignment to EPSRC's strategies and research areas
Closely aligned with quantum technologies, physical sciences and ICT themes. Specifically related to Quantum Devices, Components and Systems as well as Light Matter Interaction and Optical Phenomena research areas.

- Any companies or collaborators involved'
Collaboration with Glasgow University for HfO deposition.

Publications

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