Ultrafast charge current generation and control in low-dimensional electronic systems

Abstract

We show theoretically how charge distribution in low-dimensional semiconductor heterostructures is manipulated and controlled by means of linearly polarized, strongly asymmetric electromagnetic pulses. In particular we point out the possibility of generating a charge polarization and charge currents in mesoscopic rings and how these non-equilibrium phenomena can be utilized as a source for electromagnetic radiation and for the generation of magnetic states in the rings. Possible relaxation and decoherence pathways are investigated by means of the density matrix formalism and typical time scales for the survival of the generated non-equilibrium charge distributions are estimated.