The current research activities of the Quantum Theory Group cover a wide range of activities, principally within the fields of quantum optics and quantum information, including quantum foundations. Our work is theoretical but we enjoy working closely with our experimental collaborators.
These few paragraphs are intended to convey only a flavour of our interests and highlight some of areas of expertise.
The development of quantum technologies presents both a chance to exploit to exotic quantum phenomena and also new questions for the foundations of quantum theory. We have a continuing interest and expertise in the forms of optimal measurements, including discrimination between a number of possible quantum states. Such ideas are important, in particular, in quantum communications and we have an active interest in the study of quantum cryptography.
Chirality in quantum optics
Chiral molecules are found across the natural world, for example in the amino acids that make up the building blocks of life. This means that characterisation, sorting and separation of chiral mixtures into their left- and right-handed constituents is of particular importance in pharmaceuticals, with approximately half of the drugs on the market being chiral. We use a broad range of techniques from quantum optics, cavity quantum electrodynamics and many-body physics to develop and optimise new methodologies for all-optical enantiomeric manipulation, using for example optical surface traps, matter-wave diffraction and molecular interaction within optical lattices.
Light matter interactions
The interaction between light and matter provides the most controllable arena for exploring and, indeed, exploiting quantum phenomena. The mechanical properties of light provide a wide variety of possibilities and we have explored the nature of the forces on electrons, atoms, on molecules and and macroscopic bodies including those with a magnetic response using both semiclassical methods and quantumelectrodynamics.
Quantum field theories on curved spacetime represent a first step towards including the effects of gravity into the dynamics of quantum matter fields. Among the most celebrated predictions of this theory are the evaporation of black holes in the form of a thermal Hawking radiation, or the particle creation by an expanding, or more generally non-stationary universes. In his seminal paper, Unruh realized that these phenomena are not relevant only to gravitational systems, but are instead a purely kinematical effect of quantum fields living on a (possibly effective) curved spacetime.