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Updated: Jan 20, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
10.3K
Ballistic superconductivity and tunable π-junctions in InSb quantum wells
Chung Ting Ke1, Christian M Moehle1, Folkert K de Vries1
1QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA, Delft, The Netherlands.
Nature Communications
|August 23, 2019
Summary
We demonstrate topological superconductivity in Indium Antimonide (InSb) Josephson junctions. These devices show tunable 0-π transitions, paving the way for new quantum technologies.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Information Science
Background:
- Topological superconductivity in semiconductor quantum wells requires large spin-orbit coupling.
- Indium antimonide (InSb) two-dimensional electron gases (2DEGs) possess large Landé g-factor and high mobility, ideal for superconductivity.
- Superconducting hybrid structures in InSb 2DEGs have not been previously explored.
Purpose of the Study:
- To create and investigate Josephson junctions (JJs) in high-quality InSb 2DEGs.
- To explore the potential of InSb for hosting topological superconductivity.
- To study the interplay of superconductivity, spin-orbit interaction, and magnetism in InSb.
Main Methods:
- Fabrication of planar Josephson junctions in InSb 2DEGs.
- Experimental characterization of superconductivity and response to Zeeman fields.
- In-situ tuning of junction properties using gate electrodes.
- Comparison of experimental results with theoretical models of ballistic π-Josephson junctions.
Main Results:
- Evidence of ballistic superconductivity over micron-scale lengths in InSb JJs.
- Observation of distinct supercurrent revivals under Zeeman field, indicating 0-π transitions.
- Demonstration of device design and gate control over these 0-π transitions.
- Excellent quantitative agreement between experimental data and ballistic π-JJ theory.
Conclusions:
- InSb quantum wells represent a novel and promising material platform for topological superconductivity.
- The observed tunable 0-π transitions are crucial for potential applications in quantum computing.
- This work opens new avenues for exploring fundamental physics in hybrid superconducting systems.
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