Ultrafast high THz-field photo-driven carrier dynamics and transport in nanostructures

The electronics and optoelectronics technology is increasingly dominated by nanometer scale structures. This trend is going to continue in the future driven to large extent by the perceived needs of future computing technology for higher speed, smaller footprint and improved efficiency, where logical state switching should be achieved with drastically reduced energy-per-bit cost. This entails operating nanometer scale solid state structures at high electric field strengths and in THz frequency range or on sub-picosecond time-scale. The material properties and excitations undergo profound modifications in such spatio-temporal scales as are the dynamics of the elementary scattering process and this has a strong impact on the charge carrier dynamics and transport in such nanostructures through the friction they set in at the very microscopic quantum level. The talk will summarize the status of research in this field by outlining the main regimes of carrier dynamics and transport on ultra-short temporal scales pertinent for nanostructured semiconductors and ferroelectrics in terms of simple quantum –kinetic scattering processes and induced carrier-carrier interactions and briefly discuss the issue of the quantum friction in media lacking spatial inversion symmetry. State of the art experimental studies employing optical-THz pump-probe time resolved spectroscopy illustrating pertinent charge carrier dynamics and transport in semiconductor and ferroelectric nanostructures will be presented.