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Electrical Conductivity through a Single Atomic Step Measured with the Proximity-Induced Superconducting Pair
Howon Kim1, Shi-Zeng Lin2, Matthias J Graf2
1The Institute for Solid State Physics, The University of Tokyo, 5-1-5, Kashiwa-no-ha, Kashiwa 277-8581 Japan.
Physical Review Letters
|September 24, 2016
Summary
Disordered nanostructures significantly impact 2D conductive systems. This study reveals atomic steps in metallic layers limit superconducting correlations, influencing electrical conductivity and enhancing superconductivity under specific conditions.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Surface Science
Background:
- Local disordered nanostructures critically influence transport in 2D conductive systems.
- Atomic steps in thin metallic films can alter electronic properties.
Purpose of the Study:
- To microscopically measure electrical conductivity across atomic steps in a 2D metallic system.
- To investigate the role of local defects and steps on superconducting pair correlations.
Main Methods:
- Utilized scanning tunneling microscopy (STM) to probe superconducting pair correlation.
- Measured the reduced density of states at the Fermi energy to evaluate transport properties.
- Investigated a one-monolayer lead (Pb) metallic phase on a silicon (Si(111)) substrate.
Main Results:
- Atomic steps contribute significantly to the total resistance of nominally flat 2D metallic surfaces.
- Steps were found to terminate the propagation of superconducting pair correlations.
- Superconductivity enhancement was observed near steps due to reflectionless tunneling within the coherence length.
Conclusions:
- Atomic steps are crucial determinants of electrical transport in 2D metallic systems.
- Understanding step-induced effects is vital for controlling superconductivity in nanoscale devices.
- Proximity-induced superconductivity is sensitive to surface morphology and defects.
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