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Hard gap in epitaxial semiconductor-superconductor nanowires
W Chang1, S M Albrecht2, T S Jespersen2
11] Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark [2] Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature Nanotechnology
|January 13, 2015
Summary
Researchers achieved a hard superconducting gap in semiconductor nanowires using the proximity effect. This breakthrough is crucial for developing topological superconductivity and advancing quantum information processing with gate-tunable hybrid systems.
Area of Science:
- Condensed matter physics
- Materials science
- Quantum computing
Background:
- Superconductivity applications require electrostatic control, similar to semiconductors.
- Topological superconductivity is promising for quantum information processing.
- Previous semiconductor-superconductor hybrids had subgap states, hindering topological protection.
Purpose of the Study:
- To induce a hard superconducting gap in a semiconductor via the proximity effect.
- To develop a gate-tunable hybrid system for topological superconductivity.
- To overcome limitations of previous proximitized semiconductor systems.
Main Methods:
- Fabrication of epitaxial InAs-Al semiconductor-superconductor nanowires.
- Induction of superconductivity through the proximity effect.
- Characterization of the superconducting gap and subgap states.
Main Results:
- A hard superconducting gap was successfully induced in the InAs-Al nanowires.
- The system demonstrated favorable material properties and gate-tunability.
- The absence of significant subgap states was confirmed.
Conclusions:
- The InAs-Al nanowires provide a robust platform for topological superconductivity.
- This hybrid system is suitable for quantum information processing and mesoscopic superconductivity studies.
- The hard gap overcomes a critical obstacle in realizing protected quantum states.
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