Li-K mixture lab

We are interested in the many-body physics of impurities in a fermionic environment under conditions of strong interactions. Our experimental model system consists of fermions (K-40) or bosons (K-41) in an optically trapped sea of fermions (Li-6). Interaction tuning is provided by interspecies Feshbach resonances. We prepare Fermi polarons as microscopic impurities or small Bose-Einstein condensates as mescoscopic impurities, and study the fundamental interactions and the static and dynamic properties using various experimental tools.

The team on 02 Mar 2018 at Maria Waldrast: Tanner Grogan, Andrea Bergschneider, Cosetta Baroni, Thomas Öttl, Emil Kirilov, Isabella Fritsche, Richard Schmidt (external collaboration partner), Rianne Lous, Bo Huang, Jook Walraven, Rudi Grimm

Our work is funded by  the Austrian Science Fund FWF within SFB FoQuS (project part P04).

Fermi impurities: Polarons and beyond

Mediated interactions between Fermi polarons and the role of impurity quantum
C. Baroni, B. Huang (黄博), I. Fritsche, E. Dobler, G. Anich, E. Kirilov, R. Grimm, M. A. Bastarrachea-Magnani, P. Massignan, G. Bruun

Stability and breakdown of Fermi polarons in a strongly interacting Fermi-Bose mixture
I. Fritsche, C. Baroni, E. Dobler, E. Kirilov, B. Huang (黄博), R. Grimm, G. Bruun, P. Massignan
Phys. Rev. A 103, 053314 (2021); arXiv:2103.03625

Ultrafast many-body interferometry of impurities coupled to a Fermi sea
M. Cetina, M. Jag, R. S. Lous, I. Fritsche, J. T. M. Walraven, R. Grimm, J. Levinsen, M. M. Parish, R. Schmidt, M. Knap, E. Demler
Science 354, 96 (2016); arXiv:1604.07423

Decoherence of Impurities in a Fermi Sea of Ultracold Atoms
M. Cetina, M. Jag, R. S. Lous, J. T. M. Walraven, R. Grimm, R. S. Christensen, G. M. Bruun
Phys. Rev. Lett. 115, 135302 (2015); arXiv:1505.00738

Metastability and coherence of repulsive polarons in a strongly interacting Fermi mixture
C. Kohstall, M. Zaccanti, M. Jag, A. Trenkwalder, P. Massignan, G. Bruun, F. Schreck, R. Grimm
Nature 485, 615 (2012); arXiv:1112.0020

BEC in a Fermi sea

BEC immersed in a Fermi sea: Theory of static and dynamic behavior across phase separation
B. Huang (黄博)
Phys. Rev. A 101, 063618 (2020); arXiv:2004.09227

Breathing Mode of a BEC Repulsively Interacting with a Fermionic Reservoir
B. Huang (黄博), I. Fritsche, R. S. Lous, C. Baroni, J. T. M. Walraven, E. Kirilov, R. Grimm
Phys. Rev. A 99, 041602(R) (2019); arXiv:1812.06445

Probing the Interface of a Phase-Separated State in a Repulsive Bose-Fermi Mixture
R. S. Lous, I. Fritsche, M. Jag, F. Lehmann, E. Kirilov, B. Huang (黄博), R. Grimm
Phys. Rev. Lett. 120, 243403 (2018); arXiv:1802.01954

Thermometry of a deeply degenerate Fermi gas with a Bose-Einstein condensate
R. S. Lous, I. Fritsche, M. Jag, B. Huang (黄博), R. Grimm
Phys. Rev. A 95, 053627 (2017); arXiv:1702.02772

Ultracold molecules and few-body phenomena

Lifetime of Feshbach dimers in a Fermi-Fermi mixture of Li-6 and K-40
M. Jag, M. Cetina, R. S. Lous, R. Grimm, J. Levinsen, D. S. Petrov
Phys. Rev. A 94, 062706 (2016); arXiv:1608.07425

Observation of a Strong Atom-Dimer Attraction in a Mass-Imbalanced Fermi-Fermi Mixture
M. Jag, M. Zaccanti, M. Cetina, R. S. Lous, F. Schreck, R. Grimm, D. S. Petrov, J. Levinsen
Phys. Rev. Lett. 112, 075302 (2014); arXiv:1311.5146