Selective-Area-Grown Semiconductor-Superconductor Hybrids: A Basis for Topological Networks

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Computing

Background:

• Semiconductor-superconductor heterostructures are crucial for topological quantum computing.
• Existing platforms face challenges in scalability and precise network design.

Purpose of the Study:

• To introduce a novel platform for creating arbitrary semiconductor-superconductor networks.
• To investigate the fundamental physical properties of these hybrid nanowires.
• To demonstrate their potential for scalable topological quantum applications.

Main Methods:

• Selective area growth of hybrid Indium Arsenide/Aluminum (InAs/Al) nanowires using molecular beam epitaxy.
• Fabrication of complex networks with loops and branches.
• Low-temperature electrical transport measurements.

Main Results:

• Observation of a hard induced superconducting gap.
• Unpoisoned 2e-periodic Coulomb blockade with temperature-dependent 1e features.
• Overshoot in Coulomb peak spacing, indicating an oscillating discrete near-zero subgap state.
• Evidence of strong spin-orbit coupling and a coherence length of several microns in a loop network.

Conclusions:

• The developed InAs/Al nanowire platform enables the construction of arbitrary semiconductor-superconductor networks.
• The observed properties are consistent with theoretical predictions for topological systems.
• This platform holds significant promise for scalable topological quantum networks and other advanced applications.