Heidelberg 2015 – wissenschaftliches Programm
A 22.6: Vortrag
Mittwoch, 25. März 2015, 12:15–12:30, M/HS1
Fast Dynamics of a Fermi Impurity — Marko Cetina1, •Michael Jag1,2, Rianne Lous1,2, Rudolf Grimm1,2, Rasmus Sørensen3, and Georg Bruun3 — 1IQOQI, Österreichische Akademie der Wissenschaften, Innsbruck, Austria — 2Inst. für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria — 3Department of Physics and Astronomy, University of Aarhus, Aarhus, Denmark
We use Ramsey and spin-echo spectroscopy to probe the dynamics of a 40K impurity in a degenerate Fermi sea of 6Li atoms. At slow timescales (t>200 µs), the evolution of the impurity is dominated by elastic collisions with the background 6Li atoms. The measured rate of elastic collisions as a function of the interaction strength and temperature is in very good agreement with the Fermi liquid picture. We employ a laser-induced resonance shift to rapidly vary the interaction strength and perform quenches of the impurity into the strongly interacting regime. At very short times after the quench (t<20 µs), we observe quantum dynamics of the impurity interacting with the Fermi sea. This investigation opens the possibility to observe the pairing dynamics in a Fermi gas and the formation of polaron states.