Quantum dynamics of atomic and molecular systems

Our group studies atomic and molecular quantum systems with respect to their interactions on different levels of complexity. Of special importance is the application and extension of modern methods for the manipulation and quantum control to many-body quantum systems, in particular using coherent light. The systems under investigation range from highly excited Rydberg atoms over atomic and molecular quantum gases to molecular aggregates. The group develops technologies for trapping and cooling of neutral atoms as well as quantum-state sensitive diagnostics.

Latest news from the lab

Nonlinear optical response in Rydberg-EIT medium: paper published in Phys. Rev. A 06.12.2019
Annika Tebben

This month, our paper on a "Blockade-induced resonant enhancement of the optical nonlinearity in a Rydberg medium" got published in Phys. Rev. A! We predict the enhancement of the nonlinear optical response of the Rydberg gas as a consequence of a two-photon process that resonantly couples electronic states of a pair of atoms dressed by a strong control field. Moreover, we propose a realistic experimental scenario to observe the resonance by performing transmission measurements

Reference:
A. Tebben et al., Blockade-induced resonant enhancement of the optical nonlinearity in a Rydberg medium, Phys. Rev. A 100, 063812, (2019), or see our full list of publications
Dr. Clément Hainaut is now an Alexander von Humboldt Fellow 28.02.2019
Annika Tebben

Congratulations to Clément Hainaut who was awarded an Alexander von Humboldt Fellowship! Clément joined the Rydberg team as a postdoc for investigating relaxation dynamics of Rydberg spin systems as well as nonlinear photon interactions in a Rydberg EIT medium!


Annika Tebben receives Otto-Haxel-Prize for her Master thesis 27.10.2018
Annika Tebben

During her Master thesis Annika Tebben investigated the nonlinear optical response of an interacting Rydberg gas under conditions of electromagnetically induced transparency. In collaboration with the group of Thomas Pohl (Aarhus) she found a method to resonantly enhance the associated nonlinear susceptibility. For her outstanding work Annika was awarded the Otto-Haxel-Prize of the department of physics and astronomy of Heidelberg University. Congratulations!


For more highlights see our news page

Research topics

Mixtures of ultracold atoms and molecules

In this experiment we use a mixture of two different alkali metals: cesium and lithium. This gives us the possbility to form ultracold LiCs dimers. These molecules have an extremely large electric dipole moment which promises many new experiments. For example, the molecules can be orientated in an external electric field.

Strongly-correlated Rydberg quantum gases

Rydberg atoms are atoms in highly excited electronic states. These atoms are very sensitive to external fields and experience extremely strong interactions with other Rydberg atoms. This gives us a model system for studying strongly-correlated quantum systems that is highly controllable and completely governed by interatomic interactions.

Collisions of highly charged ions and cold atoms

We are currently setting up this new experiment. Our goal is to investigate multiple electron capture using the combined techniques of magneto-optically cooling and trapping of the target atoms and using recoil ion momentum spectroscopy.

Hybrid ion atom trap for cold chemistry experiments

Interactions between ions and neutrals play an important role in all kind of chemical reactions. In order to gain a full understanding of these systems we are trying to observe reactions at ultra-low temperatures. In this regime the reaction dynamics are no longer concealed by the thermal movement of the particles.

Rydberg physics with ultracold two-electron systems

We are setting up an experiment to study the physics of two-electron Rydberg atoms using a quantum gas of ultracold strontium. The experiment is located at the University of Science and Technology of China (USTC Shanghai Institute for Advanced Studies). First studies will be aiming to explore many-body effects induced by the long-range interactions between highly excited strontium Rydberg atoms, using the inner electron to control the atom's motion and to detect single Rydberg atoms.