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Updated: May 23, 2026
05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Prepatterned Superconducting Contacts for Clean Superconductor-Topological Material Interfaces Enabling Long-Range
Yong-Bin Choi1,2, Chang-Won Choi3, Luke Holtzman4
1Department of Physics, Pohang University of Science and Technology, Pohang-si, Gyeongsangbuk-do 37673, Republic of Korea.
Nano Letters
|May 22, 2026
Summary
Researchers developed a new method for fabricating superconducting devices using topological materials (TMs). This technique improves interface quality, leading to enhanced performance in Josephson junctions and enabling reproducible, large-scale platforms.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Information Science
Background:
- Achieving phase-coherent superconducting proximity in topological materials (TMs) is crucial for quantum applications.
- Conventional top-contact fabrication methods often lead to degraded superconductor-topological material (SC-TM) interfaces due to oxidation and disorder.
Purpose of the Study:
- To introduce and validate a novel prepatterned superconducting bottom-contact architecture for vdW TMs.
- To overcome the limitations of conventional fabrication techniques and improve SC-TM interface quality.
Main Methods:
- Fabrication of MoRe/Au superconducting bottom contacts prior to van der Waals (vdW) crystal transfer.
- Characterization of WTe2- and Bi1.5Sb0.5Te1.7Se1.3-based Josephson junctions using the new architecture.
- Interface analysis using cross-sectional scanning transmission electron microscopy/energy-dispersive spectroscopy.
Main Results:
- The prepatterned bottom-contact architecture yields systematically larger IcRN values compared to top contacts.
- Demonstrated longer-ranged superconducting coupling in Josephson junctions.
- Revealed atomically abrupt and chemically well-separated SC-TM interfaces via advanced microscopy.
Conclusions:
- The prepatterned superconducting bottom-contact approach provides a practical and reproducible method for fabricating high-performance Josephson junctions in vdW TMs.
- This architecture is essential for developing micrometer-scale Josephson platforms for topological quantum technologies.
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