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Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials
Published on: January 21, 2016
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Magnetotransport on the nano scale.
Philip Willke1, Thomas Kotzott1, Thomas Pruschke2
1IV. Physikalisches Institut - Solids and Nanostructures, University of Goettingen, 37077 Göttingen, Germany.
Nature Communications
|May 5, 2017
Summary
This study brings magnetotransport experiments to the atomic scale using scanning tunnelling potentiometry in epitaxial graphene. It reveals how magnetic fields influence electric fields and defect scattering at the nanoscale.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Macroscopic magnetotransport experiments reveal phenomena like the quantum Hall effect but lack atomic-scale resolution.
- Atomic-scale structures significantly influence transport properties, yet remain largely inaccessible to traditional methods.
- Scanning probe techniques offer high spatial resolution for probing material properties.
Purpose of the Study:
- To bridge the gap between atomic-scale structure and macroscopic transport properties.
- To adapt magnetotransport measurements to the nanoscale using advanced scanning probe methods.
- To investigate the influence of magnetic fields on electric fields and charge transport in epitaxial graphene.
Main Methods:
- Combined scanning tunnelling potentiometry with strong magnetic fields.
- Performed nanoscale magnetotransport measurements on epitaxial graphene.
- Monitored local voltage drops to analyze electric field components.
Main Results:
- Demonstrated atomic-scale control of electric field components by magnetic fields.
- Found scattering processes at localized defects to be independent of strong magnetic fields.
- Observed locally varying conductivity and charge carrier concentration in graphene sheets, differing from bulk measurements.
Conclusions:
- Scanning tunnelling potentiometry in magnetic fields enables atomic-scale magnetotransport studies.
- Graphene's nanoscale electronic properties exhibit significant local variations.
- Understanding these nanoscale phenomena is crucial for developing advanced electronic devices.
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