The physics of quantum degenerate atomic Fermi gases in uniform as well as in
harmonically trapped configurations is reviewed from a theoretical perspective. Emphasis is …

In this review, we discuss the properties of a few impurity atoms immersed in a gas of
ultracold fermions—the so-called Fermi polaron problem. On one hand, this many-body …

Recent experimental and theoretical progress has elucidated the tunable crossover, in
ultracold Fermi gases, from BCS-type superconductors to BEC-type superfluids. The BCS …

We have observed Fermi polarons, dressed spin-down impurities in a spin-up Fermi sea of
ultracold atoms. The polaron manifests itself as a narrow peak in the impurities' rf spectrum …

The notion of quasi-particles is essential for understanding the behaviour of complex many-
body systems. A prototypical example of a quasi-particle is a polaron, formed by an impurity …

Ultracold Fermi gases with tunable interactions provide a test bed for exploring the many-
body physics of strongly interacting quantum systems,,,. Over the past decade, experiments …

One of the greatest challenges in modern physics is to understand the behaviour of an
ensemble of strongly interacting particles. A class of quantum many-body systems (such as …

The interplay of quantum statistics and interactions in atomic Bose–Fermi mixtures leads to a
phase diagram markedly different from pure fermionic or bosonic systems. However …

The dynamics of a single impurity in an environment is a fundamental problem in many-body
physics. In the solid state, a well known case is an impurity coupled to a bosonic bath (such …

We employ radio-frequency spectroscopy to investigate a polarized spin mixture of ultracold
Li 6 atoms close to a broad Feshbach scattering resonance. Focusing on the regime of …