Project B5

Ultrafast Coherent STIRAP-Manipulations of Longlived Excitations in Electrically Tunable Semiconductor Artificial Atoms and Molecules

PIs: Dr. M. Betz, Prof. Dr. J. Finley


The focus of project B5 will be to apply quantum optical techniques (Stimulated Raman transitions and electromagnetically induced transparency) to coherently manipulate spin and charge degrees of freedom with high fidelity. From the outset, our studies will be based on electrically tunable QD-molecules where the electronic coupling between the upper and lower dots can be controlled using static electric fields.

The overall goals by of the project are:

  • The demonstration of ultrafast all-optical readout of single spin and charge qubits in a single nanostructure.
  • The demonstration of high fidelity state preparation by spontaneous Raman scattering for electron and hole spin qubits.
  • The refinement of our ultrafast all optical readout techniques and the development of entirely new electrical readout methods
  • The coherent manipulation of a single electron and hole spin by stimulated Raman transitions in an individual QD-molecule.

Project B5 combines the unique expertise of the two groups working on the fabrication, characterization and control of spin and charge (J. J. Finley, Walter Schottky-Institut) and ultrafast spectroscopy and quantum optics of semiconductor nanostructures (M. Betz, Physik-Department E11)  working towards the implementation of novel qubit concepts based on vertically stacked pairs of quantum dots (QD-molecules) and fully coherent few particle systems.

For more information about the groups involved please visit their web sites

Nanostructure Photonics Group of Prof. J. J. Finley (

and the

Group of PD M. Betz ( at the Physik-Department E11.