Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
TT: Fachverband Tiefe Temperaturen
TT 33: Superconductivity, Measuring Devices, Matter at Low Temperature: Poster Session
TT 33.32: Poster
Mittwoch, 28. März 2012, 15:00–19:00, Poster B
Anisotropic magneto-transport in a Bi-2201 high-Tc superconductor — •Thorsten Jacobs1, Sven-Olof Katterwe1, Andreas Rydh1, Holger Motzkau1, Toni Helm2, Mark V. Kartsovnik2, Andrey Maljuk3, Erik Kampert4, Frederik Wolff-Fabris4, and Vladimir M. Krasnov1 — 1Department of Physics, Stockholm University, AlbaNova University Center, 10691 Stockholm, Sweden — 2Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748, Garching, Germany — 3Leibniz Institute for Solid State and Materials Research IFW Dresden, 01171 Dresden, Germany — 4Hochfeld-Magnetlabor Dresden, Helmholtz Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
The single-CuO2 plane cuprate superconductor Bi2+xSr2−yCuO6+δ is characterized by a relatively low critical temperature and upper critical field. This allows for a complete suppression of superconductivity at low T and thus opens a possibility to study the normal-state properties with a low interference of thermal fluctuations.
We present magnetotransport measurements of small mesa structures (1 to 25 µm2) of Bi-2201 single crystals with a Tc of only ∼4 K. The tunneling conductance in the superconducting state exhibits gap-like characteristics that vanish at Tc or at a modest Hc2 ∼10 T. However, a profound negative c-axis magnetoresistance persists in the normal-state without saturating at fields up to H=65 T. This is likely due to a magnetic field suppression of an antiferromagnetic or spin/charge density wave order and provides evidence for a different origin of superconductivity and the pseudogap in cuprates.