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.
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
statistics
C. Baroni, B. Huang (黄博), I. Fritsche, E. Dobler, G. Anich, E. Kirilov, R. Grimm, M. A. Bastarrachea-Magnani, P. Massignan, G. Bruun
arXiv:2305.04915
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
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