Mr Thomas Collier

PhD Project

Carbon Nanotube Arrays for Terahertz Generation: Theory and Applications

 

Prof. Mikhail Portnoi, Prof. Euan Hendry and Prof. Geoff Nash

 

The project will be focused on terahertz properties of a composite of carbon nanotubes in an epoxy, which represent an archetypal metamaterial in which sub-wavelength inclusions drastically modify the optical properties of the matrix.

The prospective PhD student will study interband optical transitions and excitons in narrow-gap (quasi-metallic) carbon nanotubes which happen to be in typically in the highly sought after range of 0.5 to 5 THz as well as plasmonic absorption of the nanotubes which is enhanced at the same frequencies. The emphasis will be given to collective effect caused by a large number of nanotubes in the matrix and to the influence of external optical excitation. The main goal will be to model a system consisting of a properly designed optically pumped THz cavity where the THz gain exceeds plasmonic absorption. The physics behind this project involves many-body electron phenomena including excitons and plasmons in quasi-relativistic low-dimensional systems (narrow-gap carbon nanotubes) and quantum optics including multiple oscillators in a cavity. This will require serious theoretical study, supervised by Prof. Portnoi, which will be at every stage discussed with experimentalists actively working in this field (Prof. Hendry and Prof. Nash). The unique opportunity will be given to design and even perform relevant experiments in Prof. Hendry’s laboratory. The project will involve direct cooperation with several overseas research centres with travel support provided by various EU-funded collaborative research projects.

 

The relevant background for this project is available from the recent review article by R.R.Hartmann, J. Kono, and M.E.Portnoi "Terahertz science and technology of carbon nanomaterials", Nanotechnology 25, 322001 (2014).