Addressing bandwidth mismatch in quantum frequency conversion

Lead Research Organisation: University of Bath
Department Name: Physics

Abstract

The NQIT (Networked Quantum Information Technologies) Hub, is part of the UK National Quantum Technology Programme. Led by the University of Oxford and comprised of 9 universities and over 30 companies, NQIT's primary objective is to build a 400-qubit engine (Q20:20) that will be a major component in the first generation of quantum computers.
In connection with this goal, a further aim of NQIT is to perform investigations supporting the inclusion of Q20:20 in a wider quantum network. These investigations include the requirement that the information output from Q20:20 and its comprising qubits are compatible with current optical fibre communication networks which operate at wavelengths around 1550nm. The NQIT qubits output photons at wavelengths of 422nm or 1092nm requiring some intermediate wavelength conversion process for low-loss fibre transmission.

This PhD project will continue and expand on the work of PhD students working at the University of Bath, also under the supervision of Dr Peter Mosley. Currently, these projects focus on the reliable production of single photons at a wavelength that emulates those output by Q20:20 and the subsequent frequency conversion of these photons through spontaneous four-wave mixing (SFWM) processes. To date, conversion investigations have been performed on picosecond weak coherent states. While relevant, this represents a significant bandwidth disparity from the nanosecond-duration pulses actually output by Q20:20. Thus, alternate approaches must be explored relating to both the production of photons emulating this emission and the frequency conversion process. This work will largely be investigatory and involve modifications to the SFWM approach currently implemented. A prominent avenue of inquiry will look at the use of alternate single-photon source designs, for example microresonators, as well as making use of the University's optical fibre fabrication facilities to realise and implement new frequency-conversion strategies. The project will be carried out within the Centre for Photonics and Photonic Materials in the Department of Physics.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R513295/1 01/10/2018 30/09/2023
2128781 Studentship EP/R513295/1 01/10/2018 31/03/2022 Ross CHALLINOR