Interfacing solid state single emitters with atomic quantum memories

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Single organic molecules such as dibenzoterrylene (DBT) are excellent solid-state sources of single photons. Their emission wavelength coincides with electronic transitions in rubidium (780 - 795 nm) and emission linewidths at low temperature reach the lifetime limit (40 MHz). As such the photons generated using DBT are compatible with various quantum memory protocols using both warm and cold atomic ensembles. This PhD project will investigate routes to enhancing the emission of DBT molecules and increasing the subsequent collection efficiency of photons from single molecules. To do this I will perform nanophotonic modelling and fabrication to make waveguide and cavity structures. These will then be characterized at cryogenic temperature using confocal microscopy and laser fluorescence spectroscopy. Meanwhile, I will develop the apparatus required to demonstrate quantum memory protocols in rubidium. This will involve modelling the quantum memory, building warm atomic vapour setups, building a magneto-optical trap system to create cold clouds of atoms, and using fast intensity modulation of lasers to create the optical pulses needed to store and retrieve photons. Several memory protocols will be investigated including electromagnetically induced transparency, Autler-Townes splitting, off-resonant cascaded absorption, and Raman memories. I will then combine the molecule and atom experiments together to demonstrate the storage and retrieval of photons generated using a single molecule using an atomic vapour. In addition, atomic frequency conversion schemes will be investigated to allow for efficient conversion to telecommunication band photons to enable the possibility of an entanglement swapping across the University of Bristol campus.