Berlin 2012 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 13: Transport: Poster Session
TT 13.19: Poster
Montag, 26. März 2012, 15:00–19:00, Poster B
Transport measurements on single Bi nanowires at temperatures below 1 K — •Arnold Seiler1, Christopher Reiche1,2, Torben Peichl1, Sven Müller3, Maria E. Toimil-Molares3, Christina Trautmann3, and Georg Weiss1,2 — 1Physikalisches Institut, KIT Karlsruhe — 2Centrum für funktionelle Nanostrukturen, KIT Karlsruhe — 3GSI Darmstadt
Bismuth is an interesting semimetal for studies of electronic transport phenomena at low temperatures and reduced dimensions due to its large Fermi wavelength and long mean free path. Previous experiments with bundles of crystalline Bi wires embedded in a polycarbonate membrane show a decrease in resistance below 300 mK. Different measurements of Bi nanowires suggest that this drop is caused by superconductivity. This may be induced by surface oxidation or surface contaminants. Our Bi wires are fabricated by electrodeposition using an ion-track etched membrane as a template. We use an all organic process to extract the nanowires from the membrane without oxidation of the surface and developed various methods to contact single Bi wires in a 4-point geometry. Thus, the transport properties of Bi nanowires were successfully measured down to temperatures below 50 mK. Obtained results indicate that, depending on the growth conditions, the wires have a tendency to become either superconducting or insulating.