Performance analysis and implementation of a scanning tunneling potentiometry setup: Toward low-noise and high-sensitivity measurements of the electrochemical potential

Open access
Date
2021-10Type
- Journal Article
ETH Bibliography
yes
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Abstract
Scanning tunneling potentiometry allows for studying charge transport on the nanoscale to relate the local electrochemical potential to morphological features of thin films or two-dimensional materials. To resolve the influence of atomic-scale defects on the charge transport, sub-µV sensitivity for the electrochemical potential is required. Here, we present a complete analysis of the noise in scanning tunneling potentiometry for different modes of operation. We discuss the role of various noise sources in the measurements and technical issues for both dc and ac detection schemes. The influence of the feedback controller in the determination of the local electrochemical potential is taken into account. Furthermore, we present a software-based implementation of the potentiometry technique in both dc and ac modes in a commercial scanning tunneling microscopy setup with only the addition of a voltage-controlled current source. We directly compare the ac and dc modes on a model resistor circuit and on epitaxial graphene and draw conclusions on the advantages and disadvantages of each mode. The effects of sample heating and the occurrence of thermal voltages are discussed. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000511390Publication status
publishedExternal links
Journal / series
Review of Scientific InstrumentsVolume
Pages / Article No.
Publisher
AIP PublishingOrganisational unit
03986 - Gambardella, Pietro / Gambardella, Pietro
Funding
163225 - Local detection of spin accumulation by scanning probe microscopy (SNF)
Related publications and datasets
Is part of: https://doi.org/10.3929/ethz-b-000540655
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ETH Bibliography
yes
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