# Freiburg 2019 – wissenschaftliches Programm

## Sitzungen | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

# FM: Fall Meeting

## FM 22: Quantum Control

### FM 22.1: Invited Talk

### Montag, 23. September 2019, 16:30–17:00, 3042

Control Engineering Taken to the Limits of Quantum Systems Theory — •Thomas Schulte-Herbrüggen^{1}, Ville Bergholm^{1}, Witlef Wieczorek^{2}, and Michael Keyl^{3} — ^{1}Dept. Chem., TU-Munich (TUM), Munich, Germany — ^{2}Dept. Microtechnology and Nanoscience, Chalmers University of Technology, Sweden — ^{3}Dahlem Centre for Complex Quantum Systems, FU Berlin, Germany

Quantum optimal control is often key to exploiting the full potential of experimental set-ups pertinent to quantum emerging technologies.

We sketch a Lie frame for quantum systems theory, where symmetries and conservation laws are in quantum Noether-type 1:1 correspondence. Thus one gets a full assessment of controllability, obervability, and accessibility in quantum engineering. We now see which symmetries to break for more control and we show how to apply optimal control to exploit quantum dynamics within the enlarged accessible territory.

Our recent proposal for an optomechanical oscillator extended by a two-level atom perfectly illustrates these principles: without breaking the system symmetries of the optomechanical oscillator, one can only interconvert *within* states of the same Wigner negativity. Coupling to the atom breaks the symmetry and thus allows to go *between* them, e.g., from Gaussian states to non-classical ones.

The example thus elucidates guiding principles for quantum technologies 2.0.