The scenario of a mobile impurity immersed in a Fermi gas appears in a wide variety of systems ranging from cold atomic gases to doped semiconductors to neutron stars. Here, the impurity attractively interacts with the surrounding fermions and becomes “dressed” by excitations of the Fermi gas to form a quasiparticle, a particle-like object with modified properties from that of the bare impurity. In this talk, I will discuss how cold atoms can provide fundamental insights into the nature of these quasiparticles, particularly how they can break down in a manner not previously explored in Fermi systems. Furthermore, I will show how the dynamics of impurities driven by external fields can reveal quantum many-body phenomena such as the orthogonality catastrophe.
Host: Nir Navon (nir.navon@yale.edu)
