We are a research group based at the School of Physics and Astronomy at Queen Mary University of London and at the Department of Materials at the University of Oxford.
Our main research is focused around the question ‘How does electricity flow through an object the size of a single molecule?‘ This covers a broad range of topics – from fundamental studies of quantum transport in carbon nanostructures and electron-phonon interaction in single-molecule junctions, to applications including molecular biosensors and phase change memories.
Tuning quantum interference
The quest for molecular structures exhibiting strong quantum interference effects in the transport setting has long been on the forefront of chemical research. We have found that the unusual geometry of spiro-conjugated systems gives rise to complete destructive interference in the resonant-transport regime. This results in a current blockade of the type not present in meta-connected benzene or similar molecular structures. The potential to control quantum interference in these systems could turn them into attractive components in designing functional molecular circuits. J. Phys. Chem. Lett., 2018, 9 (8), pp 1859–1865
A single-molecule heat-engine
We have used graphene nanogaps combined with gold microheaters serve to study single-molecule thermoelectricity, and found that the power factor of graphene–fullerene junctions can be tuned over several orders of magnitude to a value close to the theoretical limit of an isolated Breit–Wigner resonance. This data suggest that the power factor of an isolated level is only given by the tunnel coupling to the leads and temperature. These results open up new avenues for exploring thermoelectricity and charge transport in individual molecules and highlight the importance of level alignment and coupling to the electrodes for optimum energy conversion in organic thermoelectric materials. Nano Lett., 2017, 17 (11), pp 7055–7061
We acknowledge funding from the following: