CLOSED Dr D C Smith EPSRC Mid Infrared Spectroscopy

The aim of this project is to exploit pulsed, coherent sources of mid-infrared light to aid our understanding of a group of materials called the strongly-correlated electron systems. Mid-infrared spectroscopy has long been used as a principle means of investigating the electronic properties of solids. Pulsed, coherent sources of light have two main features which extend the capabilities of mid-infrared spectroscopy; 1. they are much brighter, alllowing experiments to be done on materials which are only weakly absorbing e.g. single molecules, and 2. they are made up of very short pulses, which allows measurements of dynamics of materials which are out of equilibrium, due to being excited by a laser pulse, on a femtosecond timescale (light takes 3fs to travel 1um at 30,000,000 meters per second). During this project we will investigate three strongly-correlated systems; high temperature superconductors, nickelates and carbon nanotubes. The high temperature superconductors hold the record for the material which shows superconductivity, the passing of electrical current with energy loss and exclusion of magnetic fields, at the highest temperatures. The nickelates are of interest becuase it has been shown that the electrons in them form stripes of charge instead of being distributed throughout the material. Carbon nanotubes are sheets of graphite rolled up into a very small, 1-3 nanometer, tube. It has been proposed that they may play a part in a number of new technologies and in particular in the next generation of microelectronics.