Research Fellows Directory
Professor Stephen Barnett FRSE
University of Glasgow
At a fundamental level the limits to precision and to what can be achieved in harnessing the physical world are set by quantum phenomena. This is true for the observations that limit our setting of standards for timing (as used in GPS) and for our control of the nano-scale world of molecules and quantum dots. The work undertaken in this project aims to explore these quantum limits, and in doing so, to devise new and practical techniques for enhancing observation and control.
Chiral molecules are those that have distinct mirror images, with both left-handed and right-handed forms being possible, and important examples pervade the natural world. They include the sugars, the amino acids from which we are built and also many pharmaceuticals including ibruprofen. In each case, one form is useful but the other is not. Yet it is no easy task either to determine which of the two (or more) possible forms is present and also to separate these from a mixture. Part of my task is to address both of these and my approach is to use light and other electromagnetic waves to do this. Key ideas under development are a spectroscopic device for distinguishing between the mirror-image forms and an in-depth study of chirally-selective forces that may make it possible to separate them.
A fundamental study of quantum forces can throw up surprises, which is part of the fascination. My studies this year have revealed two unexpected phenomena. These are the presence of a friction acting on a moving atom as it emits light and the existence or phase vortices (analogous to the vortex at the centre of a tornado or in the water emptying your bath) for rapidly moving electrons. The existence of the former may be important in high-precision optical measurements and the latter as a tool in electron microscopy.
Interests and expertise (Subject groups)