Proximity-induced supercurrent through topological insulator based nanowires for quantum computation studies

Area of Science:

• Condensed Matter Physics
• Quantum Computing
• Materials Science

Background:

• Topological insulators (TIs) are predicted to host Majorana fermions in their surface states, crucial for fault-tolerant quantum computation.
• Current Majorana-based quantum computing architectures face scalability challenges due to reliance on complex one-dimensional quantum wire networks.

Purpose of the Study:

• To engineer robust superconductivity in topological insulator nanowires for scalable quantum computing applications.
• To investigate the potential of proximity-induced superconductivity in Bi2Se3 nanowires coupled to superconducting electrodes.

Main Methods:

• Fabrication of topological insulator (Bi2Se3) nanowire junctions using milling techniques.
• Proximity coupling of Bi2Se3 nanowires to conventional s-wave superconducting (W) electrodes.
• Characterization of superconducting properties, including critical current (IcRN) and upper critical magnetic fields.

Main Results:

• Demonstrated robust superconductivity in Bi2Se3 nanowire junctions, enabling long-range proximity-induced superconducting order.
• Achieved high IcRN products, indicating efficient propagation of superconductivity through ballistic topological surface states.
• Observed large upper critical magnetic fields surpassing the Chandrasekhar-Clogston limit, suggesting robust superconductivity with spin-triplet Cooper pairing.
• Reported an unconventional inverse relationship between IcRN and nanowire junction width.

Conclusions:

• The developed nanowire junction architecture offers a scalable platform for realizing Majorana-based quantum computation.
• The findings highlight the critical role of topological surface states in mediating long-range superconductivity.
• The observed unconventional properties suggest new avenues for controlling and utilizing superconductivity in topological materials.