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

Floquet Hamiltonian engineering of an isolated many-body spin system: paper published in Science!28.11.2021
Sebastin Geier

This month, our paper on "Floquet Hamiltonian engineering of an isolated many-body spin system" got published in Science! In this work, by periodically driving an isolated spin system, we changed a naturally given many-body Hamiltonian into a desired target form. Using a sequence of time-periodic microwave pulses, we change the Hamiltonian of our interacting Rydberg-spin system from a Heisenberg XX-model into an effective XYZ-model with tunable symmetry. As a consequence, the magnetization relaxation dynamic of the is drastically modified. The ability to engineering a wide range of Hamiltonians opens vast opportunities for implementing quantum simulation of non-equilibrium dynamics in a single experimental setting.

Reference:
S. Geier, N. Thaicharoen, C. Hainaut et al, Floquet Hamiltonian engineering of an isolated many-body spin system, Science, Vol 374, Issue 6571, pp. 1149-1152, or see our full list of publications

For more information:
University press release: https://www.uni-heidelberg.de/en/newsroom/programmable-interaction-between-quantum-magnets


Welcome to Tobias and Michael starting their PhD in the Mixtures team15.06.2021
Eleonora Lippi

A warm welcome to our news PhDs, Micheal and Tobias. Michael starts his PhD after have concluded his master thesis in our group studying the relation between Efimov scenario and Fermi polarons. Tobias joins us from Karlsruhe where he did his master thesis on optical fiber-based micro resonators. Good luck to both!


HDVent emergency ventilator system: a child project of COVID-19 times01.04.2021
Eleonora Lippi

Our group participated to the Physics Institute’s effort to create an emergency ventilator to support patients suffering from COVID-19. David, Manuel, Eleonora, Binh and Saba gave a large contribution to this project child of this year of pandemy. The design of the HDvent Emergency Ventilator has now been published and full details are available open source on the HDVent website and on github!

Reference:
D. Grimshandl et al., The HDvent Emergency Ventilator System, arXiv:2012.13005, or see our full list of publications

For more information:
Website: HDVent
Github: HDVent on Github


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.

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.