Quantum interferences of a single quantum dot in the case of detuning

We report on highly phase sensitive measurements with a slightly detuned excitation of a quantum mechanical two-level system. It is formed by the single exciton ground state of a single quantum dot, which is incorporated in a n-i-Schottky diode. We excited the two-level system by two partly overlapping laser pulses with variable phase shift. To investigate the properties of the quantum system we determine its occupancy by measuring the photocurrent. The experimental data is compared to a numerical simulation of the system. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)