Cold atomic gases have become a paradigmatic system for exploring fundamental physics,
which at the same time allows for applications in quantum technologies. The accelerating …

After decades of improvements in cooling techniques of several atomic species and in
finding methods for the achievement of stable quantum mixtures, the field is now ready for …

The emergence of quasiparticles in interacting matter represents one of the cornerstones of
modern physics. However, in the vicinity of a quantum critical point, the existence of …

Interactions between quasiparticles are of fundamental importance and ultimately determine
the macroscopic properties of quantum matter. A famous example is the phenomenon of …

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 …

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 …

In this report we discuss the dynamical response of heavy quantum impurities immersed in a
Fermi gas at zero and at finite temperature. Studying both the frequency and the time …

When mobile impurities are introduced and coupled to a Fermi sea, new quasiparticles
known as Fermi polarons are formed. There are two interesting, yet drastically different …

Polaron quasiparticles are formed when a mobile impurity is coupled to the elementary
excitations of a many-particle background. In the field of ultracold atoms, the study of the …

Advancing our understanding of non-equilibrium phenomena in quantum many-body
systems remains one of the greatest challenges in physics. Here we report on the …