Berlin 2008 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 22: Transport: Poster Session
TT 22.51: Poster
Mittwoch, 27. Februar 2008, 14:00–18:00, Poster B
Influence of defects on universal conductance fluctuations in diffusive metallic nanowires — •Thomas Schluck1, Michael Wolz1, Vojko Kunej1, Christian Debuschewitz2, and Elke Scheer1 — 1Univ. of Konstanz, Dep. of Phys. — 2attocube AG
One of the most common methods to study quantum interference effects in diffusive nanostructures is the recording of magneto-resistance curves which exhibit reproducible variations of the resistance due Universal Conductance Fluctuations (UCF).
The UCF pattern depends on the configuration of scattering centers for electron wave functions. The question arises how the UCF pattern changes when small artificial defects are added to the scattering configuration and whether a partial correlation between the patterns persists. Therefore we investigate metallic nanowires in the diffusive regime and achieved reproducible UCF patterns at T = 4.2K and T = 2.2K for magnetic fields up to 5T. To add artificial defects to the metallic nanowires a homebuilt, low-temperature and non-magnetic STM is in use [1]. For positioning the STM-tip with respect to the sample, the STM is equipped with two slip-stick tables. The nanowire structures were fabricated by electron beam lithography, reactive ion etching, wet etching and shadow evaporation (Au, Au/Cu)[2]. With a focussed ion beam we add smooth search patterns to the sample layout as a guide to the nanowire in STM mode. UCF measurements and first successful manipulations of a nanowire are presented.
[1] C. Debuschewitz et al., J. Low Temp. Phys. 147 (2007), p.525
[2] T. Hoss et al., Europhys. Lett. 54 (2001), p.654