"Building the second quantum revolution: quantum control for quantum technologies"

Prof. Dr. Tommaso Calarco (Forschungszentrum Jülich)

Building the second quantum revolution: quantum control for quantum technologies
Quantum mechanics is at the basis of all present-day information and communication
technologies: to name just two examples, transistors and lasers would be impossible to build
without understanding the quantum behaviour of matter and light. But the control of
individual quantum systems has long been considered only a “thought experiment”,
something only possible in theory. However, today this is routinely achieved in labs around
the world, and it is the basis of quantum technologies.
To achieve this vision in real environments, we need to push our ability to control the
dynamics of increasingly complex quantum systems to its limits. In the case of quantum
systems with few particles, the decoherence occurring due to the interaction with the
environment hinders the realisation of desired processes. In quantum many-body systems,
the complexity of their dynamics makes the state preparation by external manipulation more
difficult. I will show that Quantum Optimal Control Theory provides an effective strategy to
overcome these problems. Quantum coherence is used to achieve a desired target with high
accuracy, even under real conditions. I present current experiments that have been made
possible by our new optimal control algorithm, and explain how we can use such methods to
push the limits of the physical realisation of quantum technologies.