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Details of Grant 

EPSRC Reference: EP/C539974/1
Title: Fractional Charges and Fragile Fermi Liquids
Principal Investigator: Shannon, Professor NSP
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Department: Physics
Organisation: University of Bristol
Scheme: Advanced Fellowship (Pre-FEC)
Starts: 01 January 2006 Ends: 31 December 2010 Value (£): 224,635
EPSRC Research Topic Classifications:
Condensed Matter Physics
EPSRC Industrial Sector Classifications:
Related Grants:
Panel History:
Panel DatePanel NameOutcome
18 Apr 2005 Physics Fellowship Interview Panel Deferred
07 Mar 2005 Physics Fellowships Sifting Panel 2005 Deferred
Summary on Grant Application Form
Metals like copper or gold conduct heat and electricity much better than insulating materials like rubber or polystyrene.This simple fact remained a mystery until the end of the nineteenth century, when scientists tried heating metals in a vacuum, and discovered that they could be made to emit tiny particles carrying the smallest possible electric charge --- electrons.This discovery changed the world.Quite quickly, people realised that the difference between metals and insulators is that metals contained loose electrons which are free to move around inside the metal, carrying heat and electricity, while insulators do not. And this new understanding of the electric properties of solids made possible for the first time many of the technologies which we now take for granted, including television, computers and mobile phones.For almost eighty years after the discovery of the electron, everybody was happy.Scientists felt that they understood metals and, by applying the rules which they derived, engineers were able to make electronic devices which kept getting smaller, faster and cheaper.Then, quite suddenly, everything changed.Chemists looking for new superconductors --- metals which conduct electricity without getting hot - discovered some new materials which were neither conventional metals nor insulators. These new compounds exhibit what is called Non Fermi liquid behaviour. Non--Fermi liquids conduct electricity, like conventional metals, but they do not obey the ordinary rules which govern electric currents carried by electrons. In fact electric currents in non-Fermi liquids appear to be carried by particles with only a fraction of the charge of an electron. Which, according to the established theory of metals, is impossible.Clearly, the time has come to look for a new theory of metals.My research is aimed at solving this problem. My ultimate goal is to develop a mathematical model of a non-Fermi liquid state which can be used to make predictions for experiments on non-Fermi liquid materials. So far, I have been able to overcome the first major hurdle --- finding a mathematical model based on the chemistry of real, three dimensional materials which can support particles with a fraction of the charge of an electron. The essential ingredients of this model are a strong interaction between particles and frustration --- fractional charges arise because the system is forced to choose between many equally good charge configurations.This is a big step forward, but it is by no means the end of the story. I plan to use this fellowship to explore the special properties of these fractional charges, in particular the ways in which they conduct heat and electricity. If I am successful, it will become possible to write down rules for describing the properties of non-Fermi liquids, and to begin to construct a new theory of metals for the twenty-first century.
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Organisation Website: http://www.bris.ac.uk