April 1, 2021, by Dr. Meghan Gray

Institute of Physics medals for three Nottingham professors

This is a long-overdue post to congratulate three of our professors from the School of Physics and Astronomy who won major awards from the Institute of Physics. The fact that the awards were announced in October and it’s taken this long to post this gives a small reflection into the workload we’ve been facing this year!  But it’s never too late to recognise when colleagues have done something noteworthy. Congratulations all three.

Professor Richard Bowtell received the James Joule Medal and Prize for his outstanding application of physics to the innovative development of new hardware and techniques for biomedical imaging, and their application in medicine and neuroscience.  Richard writes:

A common theme of my work has been the manipulation of magnetic fields. In magnetic resonance imaging (MRI) we need accurate control of the of magnetic fields that the water molecules experience. Early in my career I worked on ways of producing controlled magnetic fields that allow images to be created faster and with more information content. Recently it turned out that we could use the same methods inside a magnetically-shielded room to reduce the ambient field to less than 1 nT (50,000 times smaller than the Earth’s field), and this allowed us to make the first wearable magnetoencephalography system (for measuring the tiny  < 1 pT magnetic fields  due to brain activity). In between, I worked on ways of mapping the magnetic properties of brain tissue using MRI, which tell us about the amount of iron that is present (useful because iron content changes in some diseases) and helped to develop new MRI scanners that work at high magnetic field (up to 140000 times larger than the Earth’s field).  Adventures spanning 13 orders of magnitude in the magnetic field were made possible by working with great colleagues, including many Nottingham Physics students, past and present.

Professor Penny Gowland received the Peter Mansfield Medal and Prize for the major contributions she has made in developing novel techiques for quantitative Magnetic Resonance Imaging (MRI) to enable innovative, non-invasive investigations into human anatomy, physiology and biology. She writes:

I was particularly honoured by this award since I came to Nottingham specifically to work with Sir Peter Mansfield, who won the Nobel Prize in Physiology or Medicine in 2003 for his work on the invention of MRI. MRI is a fantastically versatile imaging technique and my research particularly involves expanding the capabilities of the scanners, for instance to allow us to study people moving in upright MRI scanners, and also using MRI to discover new science in the field of human biology. Working with a research fellow, I have recently discovered a new sort of contraction in the placenta and a fourth year undergraduate student has joined us to now use the MRI data try to work out the purpose of these contractions.

Professor Laurence Eaves received the Nevill Mott Medal And Prize for his outstanding contributions to the investigation of fundamental electronic properties of quantum confined systems. He explains:

Laurence Eaves presently studies the way in which electrons carry the electrical current in graphene field effect transistors. Graphene is a unique type of semiconducting crystal made up of a single layer of carbon atoms arranged in a hexagonal crystal lattice. The carbon atoms are held together by strong covalent bonds but are only weakly bonded to any material surface on which they are placed. These weak bonds are called “van der Waals bonds”.

At present, the purest graphene layers are made by exfoliation, in which a single layer of graphene is peeled off from a large crystal of graphite. At Nottingham, Laurence’s colleagues are perfecting ways of growing graphene crystals in ultra-high vacuum and at high temperatures (around 1000 degrees Centigrade) by a technique called molecular beam epitaxy in which carbon atoms are fired at the surface of an insulating crystal such as hexagonal boron nitride or sapphire. Graphene produced by these two quite different techniques provides us with an atomically thin semiconducting layer of very high purity. The figure of merit for electronic quality is the mobility of an electron moving along the graphene layer. This measures the distance an electron can travel without being scattered when a small electrical voltage is applied to the graphene.

By using our superconducting magnets we can make the current-carrying electrons bend into cyclotron orbits whose energies are quantised into well-defined levels, similar to the sharply defined energy levels of electrons in orbit around an atom. This quantisation effect allows us to examine in detail the way in which the electrons are scattered by the thermal vibrations of graphene’s carbon atoms, by residual impurities, and by the side-walls of our transistors. By means of these electrical measurements and by optical spectroscopy on graphene, boron nitride and other atomically thin “van der Waals” crystals, e.g. InSe etc., we hope to optimise these materials for future applications in quantum electronics and opto-electronics.

 

Congratulations all!

 

edited 5/4/2021:  added quote from Prof Bowtell.

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