Optical quantum memories enable quantum information carried by light to be stored and later retrieved, providing a critical building block for future quantum networks and computing architectures. These memories work by mapping quantum states of light onto ensembles of atoms, such as rare earth atoms like Er in a solid crystal. The performance of a memory, such as how long information can be stored or how faithfully it is recalled, depends on the details of the atom–light interaction.

A stand-out system for quantum memory is Er doped into the crystal Y₂SiO₅, here high efficiency and moderate storage capacities have already been demonstrated. However, current models of atom–light interaction in this material lack accuracy because they neglect crystalline birefringence and the specifics of the Er optical transition. The ultimate goal of this project is to develop a complete experimental and theoretical understanding of the Er–light interaction, and to use this knowledge to design and build high-performance quantum memories.

Projects in this area can involve: developing theoretical models of atom-light interactions, running numerical simulations of storage protocols, or carrying out experiments to measure quantum coherence times or storage dependence on external fields and polarisation. Honours and PhD projects will likely include demonstrations of state-of-the-art quantum memory performance and integration into quantum networking demonstrations.

 Students will gain skills in quantum, atomic, and solid-state physics, and data analysis. Experimental projects provide training in spectroscopy, cryogenics, and precision measurement.  Computational projects will build expertise in quantum mechanics modelling and numerical methods.

The project can be adapted to suit a range of different students. Some background in quantum physics (2nd year level) is desirable for all projects.

 For Honours and PhD projects, experience some combination of advanced quantum mechanics, atom-light physics, solid state physics, and quantum computing/quantum technology would be beneficial