Institutional research of nanoelectromagnetics


School of Physics University of Exeter, United Kingdom

We propose and justify several schemes utilizing the unique electronic properties of different types of carbon nanotubes for a broad range of applications to terahertz (THz) optoelectronics, including THz generation by hot electrons in quasi-metallic nanotubes, frequency multiplication in chiral nanotubes, and tuneable THz radiation detection and optically-pumped THz emission in armchair nanotubes in a strong magnetic field. Another direction of our research is THz applications of graphene. As a gapless semiconductor with high carrier mobility, graphene represents an ideal material for detecting THz radiation. We calculate absorption rates in graphene focusing on the effect of momentum alignment (anisotropy of the distribution function) of photoexcited carriers created by linearly-polarized excitation. In conjunction with a strong angular dependence of the tunnelling probability for graphene p-n junctions, optical alignment of momenta raises the possibility of using graphene p-n junction structures in polarization-sensitive detectors.