Regensburg 2025 – scientific programme
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O: Fachverband Oberflächenphysik
O 16: Scanning Probe Techniques: Method Development
O 16.5: Talk
Monday, March 17, 2025, 16:00–16:15, H25
True Alternating Current Scanning Tunneling Microscope (ACSTM): tunneling on insulators — •Marcel Rost1 and Milan Allan1, 2 — 1Leiden Institute of Physics (LION), Leiden, NL — 2University of Munich (LMU), Munich, Germany
Scanning Tunneling Microscopy has revolutionized our atomic scale understanding of surfaces and accelerated progress in nanotechnology. This technique, however, is restricted to metal or semiconducting samples, as it requires a tiny current to stabilize the tip-sample distance with atomic scale precision.
We developed a new imaging and feedback method that relies on true alternating current (AC) without any direct current (DC) component. This technique does not only enable the imaging on non-conducting surfaces with atomic resolution, like (thin) glass and oxides, it provides also access to high-frequency electronic sample information. We demonstrate that it is possible to measure on 22nm thick silicon oxide with 10 MHz tunneling current.
Keywords: Alternating Current Scanning Tunneling Microscope; insulator; high frequency; ACSTM