Ultrafast electric phase control of a single exciton qubit

摘要

We report on the coherent phase manipulation of quantum dot excitons by electric means. For our experiments, we use a low capacitance single quantum dot photodiode which is electrically controlled by a custom designed SiGe:C BiCMOS chip. The phase manipulation is performed and quantified in a Ramsey experiment, where ultrafast transient detuning of the exciton energy is performed synchronous to double pulse pi/2 ps laser excitation. We are able to demonstrate electrically controlled phase manipulations with magnitudes up to 3 pi within 100 ps which is below the dephasing time of the quantum dot exciton. Published by AIP Publishing.