HOT-CARRIER DYNAMICS IN MESOSCOPIC STRUCTURES

We discuss a wide variety of new phenomena caused by high levels of confinement in mesoscopic systems, which affects the dynamics and statistical distribution of the carriers. A simulation of the low-temperature transport in quantum wires shows the onset of velocity oscillations arising from optical phonon emission in moderate electric fields. At high temperatures, transport nonlinearities are manifested by high carrier mobility and substantial carrier cooling. Pronounced resonances between the optical-phonon energy and the subband separation give rise to population inversion between adjacent off-resonance subbands induced by 'phonon pumping'. Under high-field conditions carriers rapidly escape from quantum wires through intervalley scattering and real space transfer.