Research Fellows Directory
Dr Andrew Jardine
University of Cambridge
I work in the field of surface science – a field that has been consistently productive for many years. It is particularly relevant today, as almost all our interactions are through surfaces, yet there remain a huge number of unsolved problems. More specifically, I am interested in “surface dynamics”, which describe the way individual atoms and molecules move when they are 'stuck' on the surface of another material. Surface dynamics is relevant to both fundamental physics, but is also important in many technological and industrial areas.
Understanding dynamics at an atomic level is extremely difficult, as motion happens over picoseconds – much too fast to be studied with microscopy - and in general, we simply don't know what happens. I use a new technique called “helium spin-echo”, which I helped pioneer in Cambridge. We bounce helium atoms from the species moving on the sample surface and measure the Doppler shift induced in the helium atoms, which tells us about the surface motion. The technique is analogous to a an 'atomic scale radar-trap'. With our measurements, we can understand both the rate of atoms moving and the mechanism of the motion, and we can gain detailed information about the surface landscape. For example, we can identify whether particular atoms shoot over the surface like bullets, or just occasionally hop between different locations.
I hope other scientists will be able to use the new knowledge coming from my experiments in a variety of ways. The information can help understand and improve surface chemical reactions (for example, catalytically splitting water to provide hydrogen). Potentially, even a small improvement to an industrial chemical process can have a major impact. Understanding surface motion is also important in understanding friction and wear, developing new materials, and in nanotechnology. Our results can even be used to test computer models, which will help ensure other simulations are meaningful and accurate.