Controlling the capture dynamics of traveling wave packets into a quantum dot

Reiter D, Glanemann M, Axt VM, Kuhn T

Abstract

An analysis of the control of capture processes from a traveling wave packet in a semiconductor quantum wire into localized states of a quantum dot is presented. On ultrafast time scales this capture in general leads to occupations of the discrete states as well as to coherences among these states. We show that both occupations and coherences can be efficiently controlled by excitation with a pair of spatially localized laser pulses which are spatially, temporally, or spectrally displaced with respect to each other. The coherences between discrete dot states are controlled by spatially nonoverlapping pulses by varying either their spatial or their temporal displacement. For spatially overlapping pulses an effective pulse shaping occurs which modifies both occupations and coherences. By using two-color laser pulses the dot states can be selectively addressed which may result in particularly pronounced coherences.