Regensburg 2019 – wissenschaftliches Programm
O 47.5: Poster
Dienstag, 2. April 2019, 18:00–20:00, Poster D
Optimization of the energy resolution and RF capability of a 30 mK dilution refrigerator scanning tunneling microscope — •Manuel Steinbrecher1, Henning von Allwörden1, Andreas Eich1, Jan Gerritsen1, Fabian D. Natterer2, Daniel Wegner1, and Alexander A. Khajetoorians1 — 1IMM, Radboud University Nijmegen, The Netherlands — 2University of Zurich, Switzerland
For a scanning tunneling microscope (STM) operated with a metallic tip the energy resolution of the spectroscopic measurements typically is given by the effective temperature of the tunneling electrons, namely 3.5kBT. However, for temperatures below ≈ 100 mK, contributions like the electromagnetic noise inside the system and capacitive noise become more dominant [1-2].
We use a home-made dilution refrigerator (T = 30 mK) based STM , with a vector magnet established in Nijmegen to test the energy resolution of our setup. We report on superconducting measurements of Al-Al junctions. We perform measurements in different tunneling regimes and with a variety of tips, testing both tip diameters and materials and report on their significance. In this course, the system was upgraded to RF capability for electron spin resonance (ESR) experiments . Results and performance will be shown for a dilution fridge STM for the first time.
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