Quantum coherent behaviour in molecular nanostructures with multiple spin centres.

Units of quantum information, called qubits, must communicate with each other if they are to perform useful logic operations. Finding suitable scaffolds for linking chemically synthesized qubits together is crucial for the development of molecular quantum technologies. Pi-Conjugated linkers allow efficient electron transport over relatively long distances, and we are exploring how they can be used to couple qubits, such as paramagnetic metal ions. This project will investigate the effects that control exchange coupling interactions and quantum coherence (temporal and spatial) in a variety of molecular nanostructures, particularly quantum rings and linear chains of coupled paramagnetic metal ions. This research will lead to molecular materials that can be switched between states of high and low electrical conductance by using a magnetic field to change the spin state, with potential applications in data storage and logic circuits. Aims and objectives. The aim is to create molecular systems composed of many addressable qubits for testing approaches to quantum information processing and quantum sensing. This requires molecules with long spin coherence times and wavefunctions that are spatially coherent over several nanometres. We aim to exploit the unique properties of quantum physics to achieve functionality and performance that cannot be achieved using classical physics. Novelty of the research methodology. The project will exploit recent advances in synthetic organic chemistry and supramolecular chemistry to create covalent arrays of paramagnetic metalloporphyrin units, and to control the interactions between these spin centres. The magnetic properties of these materials will be investigated using state-of-the-art pulsed electron spin resonance (EPR) techniques, in combination with nuclear magnetic resonance (NMR) spectroscopy, superconducting quantum interference device (SQUID) magnetometry and theoretical simulations. The project will provide the student with a high level of training in a wide variety of relevant techniques. Alignment to EPSRC's strategies and research areas. This project falls within the EPSRC quantum technologies research area. The project is also within the theme of physical sciences, and it relates to the following EPSRC Research Areas: (a) condensed matter: magnetism and magnetic materials, (b) quantum devices, components and systems, (c) synthetic coordination chemistry, (d) synthetic organic chemistry, and (e) synthetic supramolecular chemistry. Collaborators. Characterisation of the magnetic behaviour of the new materials created during this project will be carried out through established collaborations with Prof. Christiane Timmel (Oxford University, Department of Chemistry) and Prof. Lapo Bogani (Oxford University, Department of Materials and University of Florence), and possibly also Prof. Arzhang Ardavan (Oxford University, Department of Physics). No companies are involved in this project.