Sunday, December 20, 2009

THz technique

THz frequencies are employed for interrogation at nanoscale, for their key energy and timescales, since electrons dynamics in nanostructures fall in THz frequency region. Photonics are key players for development of THz devices such as quantum cascade laser QCL or THz single photon detector.

Oxford Terahertz Photonics group
http://www-thz.physics.ox.ac.uk/spectrometer/References.html
- Cutting-edge terahertz technology, M Tonouchi, Nat. Photon., 1:97-105 (2007)
- Terahertz pulse imaging in reflection geometry of human skin cancer and skin tissue, RM Woodward, BE Cole, VP Wallace, RJ Pye, DD Arnone, EH Linfield, M Pepper Phys. Med. Biol., 47:3853 (2002)
- Thz-wave spectroscopy applied to the detection of illicit drugs in mail, A Dobroiu, Y Sasaki, T Shibuya, C Otani, K Kawase Proc. IEEE, 95:1566 (2007)

Oxford University is also home to two Interdisciplinary Research Collaboration (IRC) centres - Quantum Information Processing (QIP) and Bio-nanotechnology. QIP is a cross-disciplinary team working with industry to harness the latest developments in this field so as to manipulate, store and communicate information. The Bio-nanotechnology IRC investigates naturally occurring biomolecular nanosystems and applies this knowledge to produce artificial electronic and optical devices.
Begbroke Science Park: http://www.begbroke.ox.ac.uk/research/nanotechnology.php




THz Technique

Time domain THz technique can probe the properties of charge carriers, contacts, defects, scattering events and other phenomena in carbon nanotubes and related nanoscale materials and devices, with sub-picosecond resolution.




This schematic diagram shows some of the phenomena that can be explored: (clockwise from top left) electron–electron scattering; electron–phonon scattering; the role of structural defects; and the relative importance of single-electron and plasmon excitation. A carbon nanotube FET is also shown.

Bradley F. Habenicht & Oleg V. Prezhdo, Nanotube devices: Watching electrons in real time, Nature Nanotechnology 3, 190 - 191 (2008) Published online: 23 March 2008