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
|Review of the EU Training Network on Rydberg physics published as a special issue of the EPJ||04.01.2017|
The recently published special issue of the European Physical Journal (EPJ) reviews achievements of the EU Integrated Training Network on Rydberg Physics. The training network, which is going under the abbreviation COHERENCE and was funded from 2012 to 2015 by the European Commission, was devoted to promote young researchers in the field of Rydberg gases. The central research topic was the investigation of interactions among highly excited (Rydberg) atoms under extremely controlled conditions. This kind of research has many applications in fundamental science and technology at the crossroads between atomic, molecular and condensed matter physics, quantum optics, quantum simulation, and others. Our research group, representing Heidelberg University, was one of the leading teams among 18 European and US universities and research institutions that were involved in the network. During the project more than 100 articles in high-impact journals were published. This special issue summarizes the major scientific results of COHERENCE in a series of 15 review-style articles.
For more information:
Read the complete special issue here (open access!): Cooperativity and Control in Highly Excited Rydberg Ensembles - Achievements of the European Marie Curie ITN COHERENCE
Contribution from our group: Gavryusev et al., Interaction Enhanced Imaging of Rydberg P states, Eur. Phys. J. Spec. Top. 225, 2863 (2016)
|Interaction Enhanced Imaging of Rydberg P states published in Eur. Phys. J. Special Topics!||19.12.2016|
The Interaction Enhanced Imaging technique allows to detect the spatial distribution of strongly interacting impurities embedded within a gas of background atoms used as a contrast medium. Here we present a detailed study of this technique, applied to detect Rydberg P states.
We experimentally realize fast and efficient threephoton excitation of P states, optimized according to the results of a theoretical effective two-level model. Few Rydberg P-state atoms, prepared in a small cloud with dimensions comparable to the blockade radius, are detected with a good sensitivity by averaging over 50 shots. The main aspects of the technique are described with a hard sphere model, finding good agreement with experimental data. This work paves the way to a non-destructive optical detection of single Rydberg atoms with high spatial and temporal resolution.
Interaction Enhanced Imaging of Rydberg P states: Preparation and detection of Rydberg atoms for engineering long-range interactions, Eur. Phys. J. Special Topics 225, 2863–2889 (2016), or see our full list of publications
For more highlights see our news page
|Vladislav Gavryusev is now Dr. V. Gavryusev!||19.12.2016|
Vladislav Gavryusev from the Rydberg team successfully defended his thesis... Congratulations!
Afterwards he received his PhD hat (see picture). The hat came with a replica of one of the lasers used in the Rydberg experiment. Vladislav had to lock the laser to a little cavity and align it to the center of a mini-vacuum chamber (which was actually at room pressure...). Afterwards Vlad had to proof his german and dancing skills. In the end he mastered all the tasks his hat had to offer and now truly deserves his PhD!
Imaging of Rydberg Impurities in an Ultracold Atomic Gas, PhD thesis, or see our full list of publications
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.