Reducing Disorder in PbTe Nanowires for Majorana Research.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Quantum Computing

Background:

• Material disorder is a significant obstacle in realizing Majorana research and constraining device performance.
• Current fabrication methods often introduce surface imperfections, limiting the potential of topological quantum computing.
• Achieving atomically smooth interfaces is crucial for exotic quantum phenomena like Majorana zero modes.

Purpose of the Study:

• To overcome material challenges in Majorana research by reducing surface disorder in nanowire devices.
• To develop a novel method for fabricating low-disorder nanowires for advanced quantum applications.
• To explore the potential of lead telluride (PbTe) nanowires for topological quantum devices.

Main Methods:

• Embedding lead telluride (PbTe) nanowires within a lattice-constant-matched crystal.
• Utilizing self-organized growth to shape wire edges, creating atomically flat facets.
• Fabricating heterostructures by coupling PbTe nanowires to a lead (Pb) film.

Main Results:

• Achieved nearly atomically flat facets on PbTe nanowires through self-organized growth.
• Observed quantized conductance at zero magnetic field with channel lengths up to 1.7 μm.
• Demonstrated a large superconducting gap (1 meV) and a micrometer-scale flat interface in PbTe/Pb heterostructures.

Conclusions:

• The developed self-organized growth technique significantly reduces disorder in nanowires, meeting critical requirements for Majorana research.
• The results represent a substantial advancement over state-of-the-art III-V nanowires, offering an order-of-magnitude improvement.
• This low-disorder platform holds promise for realizing Majorana zero modes and developing novel hybrid quantum devices.