Quantum Photonic Memory for Telecommunication Networks

The project is to develop a quantum memory compatible with telecommunication infrastructure. The project will explore warm vapour and rare-earth ion doped solids to develop a quantum optical memory that: (i) operates at a telecommunication wavelength of 1550nm; (ii) accepts GHz bandwidth inputs; (iii) operates with near-unit efficiency; and (iv) has zero noise contributions on the output. This unique capability enables the candidate to enact effective storage and recall of single photons from sources based on e.g. emergent semiconductor quantum dot technology - an outstanding challenge in the quantum photonics community. This therefore provides a much-needed tool for real-world quantum networks, paving the way for disruptive quantum technologies such as secure quantum communications and photonic quantum computers.

The quantum memory will be based on the off-resonant cascaded absorption (ORCA) protocol using a two-photon ladder transition in atomic ensembles. The first step is to combine the temporal-spectral mode manipulation techniques with the ORCA protocol. The student will:
(i) investigate the coherent filtering of quantum dot emission, performing indistinguishability measurements of the stored and recalled light with the goal to increase the purity of photons.
(ii) explore multiplexing the outputs of multiple quantum dots with the goal to address the issue of poor interference of disparate emitters via temporal-spectral mode matching with the quantum ORCA memory.
(iii) investigate techniques to mitigate inhomogeneous dephasing to allow efficient use of telecommunication transitions in warm vapour and rare-earth ions for an ORCA quantum memory.