Scientific aim of the SFB 767, Controlled Nanosystems: interaction and interfacing to the macroscale

The field of nanoscience has significantly matured during the last decade. Perspectives for applications based on nanostructures have emerged which rely crucially on a precise control of the interaction between nanosystems or the influence of external fields. Our SFB has contributed significantly to the progress in nanoscience by developing control mechanisms for individual nanosystems. We have shown that achieving control by structural, optical or electric means is a promising route to an advanced understanding of mechanical, electronic, and magnetic properties of nanosystems. Our research program is organized around these topics.

The first area covers Structural and mechanical properties and here the investigations have focused on coherent mechanical excitations of membranes and beams controlled by electromagnetic fields. One main finding is the origin of mechanical damping in nanomembranes and the coherent control of a nanobeam. In future, this area will extend the research towards control of heat transport by temperature gradients.

In the second research area on Optical and electronic properties the main goal is to use the potential of optical control of nanosystems. An unprecedented level of control was achieved experimentally by two-color excitations of molecules and theoretically of spin-qubit candidates. Further major progress concerned stability of colloidal quantum dots, their control on ultrafast time scales and in magnetic fields as well as direct detection of the photonic vacuum. In future, this area will expand to an ultrafast control of the coupling between a tunnel current and photons.

The third project area, Electronic and magnetic transport properties, has elaborated on the control of electrons in single molecular junctions or quantum point contacts and the magnetization in nanostructures. As highlights we have shown how to control single spins in molecules, single electrons by voltage pulses, vibrational modes by current, and domain walls by thermal gradients. In the future, we will continue this research concentrating on the most promising aspects.

The last funding period will be devoted to fine-tuning control schemes like electrical and optical field effects on mechanical and magnetic nanosystems, molecules and semiconductor quantum dots. Based on the insights of the previous funding periods we will extend our scope to topics such as ultrafast manipulation of electronic tunneling currents and engineered heat flow in nanocontacts.