E. Scheer, formerly V. Kunej and T. Schluck
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 to 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 = 4.2 K and T = 2.2 K for magnetic fields up to 5 T.
To add artificial defects to the metallic nanowires, a homebuilt, low-temperature, and non-magnetic STM is in use. 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. With a focussed ion beam, we add smooth search patterns to the sample layout as a guide to the nanowire in STM mode.
More information available on the Nanonetz project page.