Berlin 2014 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 4: Quantum gases: Fermions
Q 4.1: Vortrag
Montag, 17. März 2014, 10:30–10:45, DO24 Reuter Saal
Conduction Properties of Ultracold Fermions — •Dominik Husmann, Sebastian Krinner, David Stadler, Jean-Phillippe Brantut, and Tilman Esslinger — Institut für Quantenelektronik, ETH Zürich, Schweiz
Out-of-equilibrium measurements on cold-atom systems pose an important experimental challenge for the understanding of many phenomena encountered in condensed matter physics. We present a fermionic 6Li cold-atom system that allows the measurement of the conductance through a narrow constriction in a two-terminal setup. Our system is analogous to and inspired by electronic transport through mesoscopic structures in solids. The system consists of two macroscopic reservoirs of ultracold 6Li atoms, which are connected by a mesoscopic narrow channel. Upon inducing a bias to the chemical potential of the two reservoirs, a particle current through the channel sets in, which restores thermal equilibrium. The dynamics of the relaxation process is analogous to the discharge of a capacitor, where the conductance is inversely proportional to the time scale. A broad Feshbach resonance between the two lowest hyperfine states of 6Li at 834 G allows to tune interparticle interactions to both weakly and strongly repulsive or attractive interacting regimes.
Upon applying a temperature bias to the reservoirs, we observe features of thermoelectricty. In a different measurement, we narrow the channel down to a one-dimensional constriction and measure current induced by applying a particle imbalance between the reservoirs.