title: Conduction of ultracold fermions through a mesoscopic channel.
abstract: In a mesoscopic conductor, electric resistance is detected even if the device is defect-free. We engineered and studied a cold-atom analog of a mesoscopic conductor. It consists of a narrow channel connecting two macroscopic reservoirs of fermions that can be switched from ballistic to diffusive. We induced a current through the channel and found ohmic conduction, even when the channel is ballistic. We measured in situ the density variations resulting from the presence of a current and observed that density remains uniform and constant inside the ballistic channel. In contrast, for the diffusive case with disorder, we observed a density gradient extending through the channel. Our approach opens the way toward quantum simulation of mesoscopic devices with quantum gases.
authors.affiliation: Institute for Quantum Electronics, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zürich, Switzerland.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Brantut
authors.forename: Jakob
authors.initials: J
authors.lastname: Meineke
authors.forename: David
authors.initials: D
authors.lastname: Stadler
authors.forename: Sebastian
authors.initials: S
authors.lastname: Krinner
authors.forename: Tilman
authors.initials: T
authors.lastname: Esslinger