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Title: Scanning probe microscope simulator for the assessment of noise in scanning probe microscopy controllers

We present an electronic circuit that allows to calibrate and troubleshoot scanning probe microscopy (SPM) controllers with respect to their noise performance. The control signal in an SPM is typically highly nonlinear—the tunneling current in scanning tunneling microscopy (STM) varies exponentially with distance. The exponential current-versus-voltage characteristics of diodes allow to model the current dependence in STM. Additional inputs allow to simulate the effects of external perturbations and the reactions of the control electronics. We characterized the noise performance of the feedback controller using the apparent topography roughness of recorded images. For a comparison of different STM controllers, an optimal gain parameter was determined by exploring settling times through a rectangular perturbation signal. We used the circuit to directly compare the performance of two types of SPM controllers used in our laboratory.
Authors:
; ;  [1]
  1. Institute of Experimental and Applied Physics, University of Regensburg, 93040 Regensburg (Germany)
Publication Date:
OSTI Identifier:
22220556
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 84; Journal Issue: 7; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; COMPARATIVE EVALUATIONS; CURRENTS; DISTURBANCES; FEEDBACK; MICROSCOPES; NOISE; PERFORMANCE; PROBES; ROUGHNESS; SCANNING TUNNELING MICROSCOPY; SIMULATORS; TUNNEL EFFECT