Enhanced Proximity Effect in Zigzag-Shaped Majorana Josephson Junctions.

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Superconductor-semiconductor-superconductor junctions are key for topological quantum computing.
• Low electron density in conventional designs limits the induced superconducting gap and Majorana mode protection due to long quasiparticle flight times.
• A large induced gap is crucial for robust Majorana states.

Purpose of the Study:

• To investigate a novel zigzag geometry for superconductor-semiconductor-superconductor junctions.
• To determine if this geometry can eliminate long quasiparticle trajectories and enhance the induced superconducting gap.
• To assess the impact on Majorana state creation and robustness.

Main Methods:

• Theoretical modeling of quasiparticle trajectories in a zigzag-shaped junction.
• Simulation of induced superconducting gap (E_{gap}) and Majorana size (ξ_{M}) for the proposed geometry.
• Analysis of device parameter sensitivity.

Main Results:

• The zigzag geometry effectively eliminates long quasiparticle flight times.
• This leads to a significant increase (over an order of magnitude) in the induced superconducting gap.
• Robust creation of Majorana states is achieved with improved gap and size parameters.

Conclusions:

• The zigzag geometry offers a promising solution for overcoming limitations in Majorana device fabrication.
• This design enhances Majorana properties and robustness.
• The geometry demonstrates insensitivity to device tuning and geometric details, simplifying fabrication and operation.