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InSbAs Two-Dimensional Electron Gases as a Platform for Topological Superconductivity.
Christian M Moehle1, Chung Ting Ke1, Qingzhen Wang1
1QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands.
Nano Letters
|November 18, 2021
Summary
Researchers engineered topological superconductivity using a novel ternary semiconductor (InSbAs) and aluminum. This new platform enables tunable spin-orbit coupling and a hard induced superconducting gap, crucial for studying Majorana zero modes.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Information
Background:
- Topological superconductivity is a frontier in condensed matter physics, with potential applications in quantum computing.
- Hybrid material systems combining superconductors and semiconductors with strong spin-orbit interaction are key experimental platforms.
- Two-dimensional electron gases (2DEGs) offer design flexibility and scalability for creating such hybrid systems.
Purpose of the Study:
- To introduce and characterize a new 2D hybrid material system for topological superconductivity research.
- To investigate the tunable spin-orbit coupling and superconducting properties of the novel material.
- To demonstrate the potential of this platform for fabricating devices relevant to Majorana zero mode studies.
Main Methods:
- Fabrication of a ternary 2DEG (InSbAs) coupled to in situ grown aluminum.
- Characterization of spin-orbit coupling strength as a function of As concentration.
- Measurement of the Landé g-factor and the induced superconducting gap at the superconductor-semiconductor interface.
- Demonstration of basic device functionalities including Josephson junctions and superconducting islands.
Main Results:
- Achieved tunable spin-orbit coupling up to 400 meV Å in InSbAs 2DEGs, exceeding binary constituents.
- Observed a large Landé g-factor (∼55) and a hard induced superconducting gap due to a clean interface.
- Successfully demonstrated phase-controllable Josephson junctions, superconducting islands, and quasi-1D systems.
Conclusions:
- The ternary InSbAs/Al 2D hybrid system is a promising new platform for exploring topological superconductivity.
- Tunable spin-orbit interaction and a robust induced superconducting gap are key advantages of this material system.
- The demonstrated device functionalities pave the way for future investigations of Majorana zero modes.
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