Conductance Quantization at Zero Magnetic Field in InSb Nanowires

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Topological phase transitions in proximitized indium antimonide (InSb) nanowires depend on ballistic electron transport.
• Quantized conductance measurements, direct evidence of ballistic transport, are challenging in 1D nanowires due to backscattering.
• Previous studies faced difficulties in observing clear signs of ballistic transport in such systems.

Purpose of the Study:

• To demonstrate consistent conductance quantization at zero magnetic field in InSb nanowires.
• To overcome the limitations of backscattering in one-dimensional systems.
• To investigate the influence of orbital effects on sub-band dispersion under varying magnetic field orientations.

Main Methods:

• Fabrication of InSb nanowires with improved nanowire-metal interfaces.
• Optimization of the dielectric environment surrounding the nanowires.
• Electrical transport measurements, including conductance quantization analysis at zero magnetic field.
• Investigation of magnetic field effects on sub-band dispersion.

Main Results:

• Consistent observation of conductance quantization at zero magnetic field was achieved.
• Improvements in interface and dielectric environment significantly reduced backscattering.
• Near-degeneracy between the second and third sub-bands was observed due to orbital effects under magnetic fields.

Conclusions:

• Ballistic electron transport in InSb nanowires can be reliably achieved through optimized fabrication and environment.
• Conductance quantization at zero magnetic field is a viable indicator of ballistic transport in these systems.
• Orbital effects play a significant role in the electronic sub-band structure of InSb nanowires.