Etching process of narrow wire and application to tunable-barrier electron pump

Area of Science:

• Quantum Optics
• Condensed Matter Physics
• Nanofabrication

Background:

• Single electron sources are crucial for establishing electric current standards.
• They are also emerging as on-demand coherent sources for fermion quantum optics.
• Fabricating these sources on GaAs/AlGaAs two-dimensional electron gas (2DEG) typically requires sub-micrometer wire etching.

Purpose of the Study:

• To establish a novel fabrication technique for single electron sources on 2DEG.
• To enable simultaneous etching of fine and coarse structures.
• To minimize damage to the fragile 2DEG during fabrication.

Main Methods:

• Utilized a combination of photolithography and electron beam lithography.
• Employed a one-step photoresist coating process.
• Developed techniques for etching sub-micrometer wires on GaAs/AlGaAs 2DEG.

Main Results:

• Successfully fabricated a single electron source on 2DEG.
• Demonstrated the source's ability to pump a fixed number of electrons per cycle using radio frequency.
• The new technique reduces the risk of damage to the 2DEG.

Conclusions:

• The established fabrication technique is effective for creating high-quality single electron sources.
• This method enhances the lithography process for fragile 2DEG materials.
• The improved single electron sources have potential applications in metrology and quantum technologies.