Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 24: Focus Session: Functional Semiconductor Nanowires II (organized by HL)

TT 24.7: Hauptvortrag

Montag, 16. März 2015, 17:00–17:30, EW 201

Quantum Transport in Core/Shell Semiconductor Nanowires — •Thomas Schäpers, Fabian Haas, Patrick Zellekens, Torsten Rieger, Tobias Wenz, Yusuf Günel, Önder Gül, Natalia Demarina, Mihail Lepsa, Hans Lüth, and Detlev Grützmacher — Peter Grünberg Institute (PGI- 9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

The transport properties of GaAs/InAs core/shell nanowires is investigated, where the highly conductive InAs shell is wrapped around an insulating GaAs core nanowire. At low temperatures pronounced flux periodic (h/e) magnetoconductance oscillations are observed, when the magnetic field is oriented along the nanowire axis. These very regular oscillations are explained by the formation of closed-loop quantum states in the tube-like InAs shell comprising a flux periodic energy spectrum. The magnetoconductance oscillations are even observed at temperatures as high as 50K. When the GaAs/InAs core/shell nanowire is contacted by two superconducting Nb electrodes the carrier transport is governed by phase-coherent Andreev reflection processes. Here, the observed oscillation period in the magneto-transport corresponds to half a flux quantum (h/2e).