Manipulating single quantum dot states in a lateral electric field

We demonstrate measurements of the quantum confined Stark effect on single self-assembled CdSe/ZnSe quantum dots. For this purpose, a nano-scaled capacitor was developed being capable of exerting lateral electric fields up to View the MathML source on single quantum dots. Stark shifts of up to View the MathML source have been obtained for the single exciton emission accompanied by a line width broadening due to field-induced carrier tunneling into the barrier. Evaluating the redshift of the luminescence signal as a function of the electric field enables us to extract the polarizability as well as information on the permanent dipole of a single quasi-zero-dimensional exciton.