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Atomic Diffusion-Induced Polarization and Superconductivity in Topological Insulator-Based Heterostructures
Xian-Kui Wei1, Abdur Rehman Jalil2, Philipp Rüßmann3,4
1Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
ACS Nano
|December 21, 2023
Summary
We discovered palladium diffusion creating electric polarization at superconductor-topological insulator interfaces. This polarization impacts interface structure and is compatible with superconductivity and topological properties, crucial for Majorana zero modes.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Superconductor-topological insulator interfaces are promising for Majorana zero modes.
- Understanding interface structure and chemistry is crucial but underexplored.
Purpose of the Study:
- Investigate structural and chemical properties of superconductor-topological insulator interfaces.
- Explore palladium diffusion and its effect on interface polarization.
- Assess the robustness of superconductivity and topological properties.
Main Methods:
- Atomic-resolution scanning transmission electron microscopy (STEM).
- Quantitative image analysis.
- First-principles calculations.
Main Results:
- Discovered palladium diffusion-induced polarization at superconductor-topological insulator interfaces.
- Nanoscale lattice strain and quintuple layer polarity control palladium diffusion.
- Superconductivity and topological properties remain robust despite broken inversion symmetry.
Conclusions:
- Interface polarization is a key factor in superconductor-topological insulator heterostructures.
- Palladium diffusion and resulting polarization must be considered for Majorana zero mode applications.
- The coexistence of electric polarization, superconductivity, and topology is essential.
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