Adiabatic Edge Channel Transport in a Nanowire Quantum Point Contact Register

Area of Science:

• Condensed Matter Physics
• Nanotechnology
• Quantum Electronics

Background:

• Quantum point contacts (QPCs) are crucial for quantum devices.
• Achieving long coherence lengths in nanowires is essential for advanced electronics.
• Ballistic transport in semiconductor nanostructures is a key research area.

Purpose of the Study:

• To demonstrate a prototype device with serially connected QPCs in an InAs nanowire.
• To investigate the effect of magnetic fields on backscattering and QPC connectivity.
• To explore the potential for controlling ballistic logic operations.

Main Methods:

• Fabrication of a quasi-ballistic InAs nanowire with multiple QPCs in series.
• Application of finite and transverse magnetic fields.
• Measurement of conductance oscillations and Shubnikov-de Haas effect.

Main Results:

• Increased backscattering length to the micron-scale at finite magnetic fields.
• Adiabatic connection of QPCs, enabling control over ballistic logic.
• Observation of Aharonov-Bohm-type oscillations and Shubnikov-de Haas effect.
• Evidence for selective population of spatially separated edge channels.

Conclusions:

• The device geometry facilitates control over ballistic logic operations.
• Spatially separated edge channels explain the absence of backscattering.
• The observed phenomena provide a new method for InAs nanowire characterization.