aqora

Repulsive polarons in a strongly interacting Fermi mixture

Christoph Kohstall, Matteo Zaccanti, Michael Jag +5 more

APSJun 1, 20120 citations

Polarons in a strongly interacting Bose-Fermi mixture

Cheng-Hsun Wu, Ibon Santiago, Jee Woo Park +3 more

APSJun 1, 20120 citations

Repulsive polarons and itinerant ferromagnetism in strongly polarized Fermi gases

Pietro Massignan, Georg M. Bruun

arXiv:1102.0121The European Physical Journal DJul 27, 2011130 citations

Repulsive Fermi Polarons in a Resonant Mixture of Ultracold Li6 Atoms

Francesco Scazza, Giacomo Valtolina, Pietro Massignan +7 more

We employ radio-frequency spectroscopy to investigate a polarized spin mixture of ultracold ^{6}Li atoms close to a broad Feshbach scattering resonance. Focusing on the regime of strong repulsive interactions, we observe well-defined coherent quasiparticles even for unitarity-limited interactions. We characterize the many-body system by extracting the key properties of repulsive Fermi polarons: the energy E_{+}, the effective mass m^{*}, the residue Z, and the decay rate Γ. Above a critical interaction, E_{+} is found to exceed the Fermi energy of the bath, while m^{*} diverges and even turns negative, thereby indicating that the repulsive Fermi liquid state becomes energetically and thermodynamically unstable.We employ radio-frequency spectroscopy to investigate a polarized spin mixture of ultracold ^{6}Li atoms close to a broad Feshbach scattering resonance. Focusing on the regime of strong repulsive interactions, we observe well-defined coherent quasiparticles even for unitarity-limited interactions. We characterize the many-body system by extracting the key properties of repulsive Fermi polarons: the energy E_{+}, the effective mass m^{*}, the residue Z, and the decay rate Γ. Above a critical interaction, E_{+} is found to exceed the Fermi energy of the bath, while m^{*} diverges and even turns negative, thereby indicating that the repulsive Fermi liquid state becomes energetically and thermodynamically unstable.

arXiv:1609.09817Physical Review LettersFeb 21, 2017267 citations

Quasiparticle Lifetime of the Repulsive Fermi Polaron

Haydn S. Adlong, Weizhe Edward Liu, Francesco Scazza +5 more

We investigate the metastable repulsive branch of a mobile impurity coupled to a degenerate Fermi gas via short-range interactions. We show that the quasiparticle lifetime of this repulsive Fermi polaron can be experimentally probed by driving Rabi oscillations between weakly and strongly interacting impurity states. Using a time-dependent variational approach, we find that we can accurately model the impurity Rabi oscillations that were recently measured for repulsive Fermi polarons in both two and three dimensions. Crucially, our theoretical description does not include relaxation processes to the lower-lying attractive branch. Thus, the theory-experiment agreement demonstrates that the quasiparticle lifetime is dominated by many-body dephasing within the upper repulsive branch rather than by relaxation from the upper branch itself. Our findings shed light on recent experimental observations of persistent repulsive correlations, and have important consequences for the nature and stability of the strongly repulsive Fermi gas.We investigate the metastable repulsive branch of a mobile impurity coupled to a degenerate Fermi gas via short-range interactions. We show that the quasiparticle lifetime of this repulsive Fermi polaron can be experimentally probed by driving Rabi oscillations between weakly and strongly interacting impurity states. Using a time-dependent variational approach, we find that we can accurately model the impurity Rabi oscillations that were recently measured for repulsive Fermi polarons in both two and three dimensions. Crucially, our theoretical description does not include relaxation processes to the lower-lying attractive branch. Thus, the theory-experiment agreement demonstrates that the quasiparticle lifetime is dominated by many-body dephasing within the upper repulsive branch rather than by relaxation from the upper branch itself. Our findings shed light on recent experimental observations of persistent repulsive correlations, and have important consequences for the nature and stability of the strongly repulsive Fermi gas.

arXiv:2005.00235Physical Review LettersSep 24, 202053 citations

The Scattering and Coherence of a Fermi Polaron

Marko Cetina, Michael Jag, Rianne S. Lous +4 more

Bulletin of the American Physical SocietyJun 3, 20140 citations

Metastability and coherence of repulsive polarons in a strongly interacting Fermi mixture

Related papers

Metastability and coherence of repulsive polarons in a strongly interacting Fermi mixture

Related papers