Optical electron spin tomography and hole spin coherence studies in (In,Ga)As/GaAs quantum dots

Abstract

Electron and hole spins confined in semiconductor quantum dots are of particular interest as candidates for the implementation of quantum bits in future quantum computers. In the first part of this thesis, the feasibility of an all-optical electron-spin tomography is demonstrated using picosecond laser pulses in the pump-probe technique. The second part focuses on hole-spin coherence. Hole-spin mode-locking under periodical laser excitation is demonstrated, which allows an investigation of hole-nuclear interactions and the measurement of the coherence time T2. This time is measured in dependence on the temperature and a dynamical decoupling protocol is presented prolonging the coherence time T2.