News & Events

26 Oct 2023 – Our article on Mediated interactions between Fermi polarons and the role of impurity quantum statistics was published in Nature Physics. Surprisingly, polarons can attract or repel each other depending on whether they are bosons or fermions. Quantum statistics makes the difference.

18 Aug 2023 – Our article on Optically trapped Feshbach molecules of fermionic Dy-161 and K-40 just came out as Editors’ suggestion in Phys. Rev. Research. The phase-space density is close to degeneracy, but surprisingly the trap light induces losses.

07 Jul 2023 – Congratulations to Marian for defending his PhD thesis “Strongly Interacting Fermi-Fermi Mixtures of Dy and K: Monte Carlo Simulations…. It is great to see how useful such simulations are for understanding the behavior of ultracold systems.

15 Jun 2023 – Our center is organizing the Introductory Course on Ultracold Quantum Gases (09 -12 July 2023). The program, giving an introduction into the fascinating research field, is addressed to students at the end of their bachelor studies or early in the master program.

06 Jun 2023 – Congratulations to Cosetta for defending her PhD thesis “Polarons and their Mediated Interactions…. Finally we see how Fermi polarons interact with each other and what a difference quantum statistics really makes.

17 Oct 2022 – Our article on Observation of low-field Feshbach resonances between Dy-161 and K-40 was just published as Editors’ suggestion in Phys. Rev. A. Accurate interaction control and molecule formation in the heteronuclear Fermi-Fermi mixture turned out to be surprisingly simple.

29 Aug 2022 – Our article on Low-field Feshbach resonances and three-body losses in a fermionic quantum gas of Dy-161 just appeared in the Ukrainian Journal of Physics. You will see a remarkable zoo of resonances. Slava Ukraini!

23 Jul 2022 – We had a great time at the International School of Physics “Enrico Fermi” on Quantum Mixtures with Ultra-Cold Atoms, which was organized in Villa Monastero in Varenna at the Lake Como. Directors: Rudi Grimm, Massimo Inguscio, Sandro Stringari. Scientific Secretary: Giacomo Lamporesi.

12 Jul 2022 – Congratulations to Elisa for defending her PhD thesis “Interaction Properties of an Ultracold Fermi-Fermi Mixture of Dysprosium and Potassium Atoms. Now we know how we can tune interactions in the mixture without losing too many atoms.

12 Sep 2021 – The BEC Senior Award goes to Rudi Grimm (IQOQI and Univ. Innsbruck) together with Tilman Esslinger (ETH Zurich). The prize, sponsored by Toptica Photonics, was awarded at the biennial BEC conference in Sant Feliu de Guixols at the Costa Brava in Spain.

10 Sep 2021 – Our new paper Measurement of the dynamical polarizabilty of Dy atoms near the 626-nm intercombination line was published in Phys. Rev. A as an Editors’ Suggestion. We introduce a scheme that works on both sides of a resonance, employing on modulation spectroscopy in an optical lattice.

02 Aug 2021 – Congratulations to Isabella for defending her PhD thesis “Strongly Interacting Fermi-Fermi and Fermi-Bose Mixtures: From Polarons to a Bose-Condensed Impurity Cloud. Now we see the difference that the quantum statistics of impurities can make.

17 May 2021 – Our new paper Stability and breakdown of Fermi polarons in a strongly interacting Fermi-Bose mixture was published in Phys. Rev. A as an Editors’ Suggestion. Employing a trapped mixture of Li-6 and K-41, we have investigated a situation where Fermi and Bose polarons coexist. The experimental work was carried in the FeLiKx lab.

12 Apr 2021 – An ERC Advanced Grant goes to Rudi Grimm. The project “SuperCoolMix” will focus on Novel Superfluids in Ultracold Fermionic Mixtures. We are very happy about excellent funding in the next 5 years and thank the European Research Council. We look forward to many exciting results to come.

01 Jul 2020 – Our Marie Sklodowska-Curie fellow Jeong Ho Han, who graduated from Seoul National University, has started his project “Strongly Interacting Mass Imbalanced Superfluid with ultracold fermions (SIMIS)”. The work will be carried out in our DyK lab.

23 May 2020 – Our paper Resonantly Interacting Fermi-Fermi Mixture of Dy-161 and K-40 just came out in Phys. Rev. Lett. The mixture now available in our DyK lab features mass imbalance, wide tunability, and collisional stability, which is a very promising combination for the realization of novel superfluids in fermionic quantum gases.

18 Apr 2019 – Our center is organizing the Introductory Course on Ultracold Quantum Gases (08 -10 July 2019), which will give a general introduction into the fascinating research field. The program is addressed to students at the end of their bachelor studies or early in the master program. Specialized knowledge is not required.

03 Apr 2019 – Our paper Breathing mode of a Bose-Einstein condensate repulsively interacting with a fermionic reservoir just came out in Phys. Rev. A. In our experiment, the small BEC is compressed by the surrounding Fermi sea, which strongly increases the frequency of the basic breathing mode.

01 Feb 2019 – We are co-organizing the Workshop on Compound (Atomic) Quantum Systems at the Lorentz Center in Leiden (20 – 24 May 2019). The workshop brings together experts of ultracold quantum gases, polar molecules, trapped ions, Rydberg and solid-state physics, quantum optics, few- and many-body theory in order to present the current status of research and discuss open questions in the field.

20 Dec 2018 – Our paper Production of a degenerate Fermi-Fermi mixture of dysprosium and potassium atoms just came out in Phys. Rev. A. In our DyK lab, we now have a deeply degenerate Fermi-Fermi mixture of a new kind available for exciting experiments aiming at novel mass-imbalanced superfluids.

05 Oct 2018 Congratulations to Rianne for defending her PhD thesis “Tunable Bose-Fermi and Fermi-Fermi Mixtures of Lithium and Potassium: Phase Separation, Polarons, and Molecules”. It is such a beautiful academic hat and the coala seems to enjoy the party as well.

11 Jul 2018 Vitaly Efimov and Rudolf Grimm received the inaugural Faddeev medal. The award ceremony took place at the XXII International Conf. on Few-Body Problems in Physics in Caen, France. In 1970, Efimov predicted that a three-body system with resonant two-body interactions can form an infinite series of bound states. First experimental evidence for the “Efimov effect” was obtained in Innsbruck in 2005.

13 Jun 2018 Our paper Probing the Interface of a Phase Separated State in a Repulsive Bose-Fermi Mixture just came out in Physical Review Letters. Now we know what happens at the interface between a Bose-Einstein condensate and a degenerate Fermi sea under conditions where both species are immiscible.

30 May 2018 Our paper Accurate Determination of the Dynamical Polarizability of Dysprosium just came out in Physical Review Letters. We show how to solve the problem of notoriously difficult measurements of atomic polarizabilities by using a reference species.