Si/SiGe QuBus for single electron information-processing devices with memory and micron-scale connectivity function.

Area of Science:

• Quantum Computing
• Solid-State Physics
• Nanotechnology

Background:

• Quantum information processing relies on the controlled transport and storage of single charge quanta.
• Existing methods for electron transport face challenges in scalability and fidelity over longer distances.

Purpose of the Study:

• To demonstrate a long-range, all-electrical quantum bus (QuBus) for adiabatic single-electron transport.
• To introduce and utilize shuttle-tomography for characterizing QuBus performance.
• To assess the feasibility of using the QuBus for initializing quantum registers.

Main Methods:

• Fabrication of a 10 μm Si/SiGe shuttle device.
• Operation of the QuBus using six voltage pulses for adiabatic electron transport.
• Characterization of shuttle fidelity using the novel shuttle-tomography technique.

Main Results:

• Achieved adiabatic transport of single electrons over 10 μm with a round-trip fidelity of (99.7 ± 0.3)%.
• Demonstrated positioning and detection of up to 34 electrons.
• Successfully initialized a register of 34 quantum dots with arbitrary single-electron patterns.

Conclusions:

• The developed QuBus offers a scalable and high-fidelity solution for long-range electron transport.
• The shuttle-tomography method provides a robust benchmark for device imperfections.
• The QuBus technology shows significant promise for advancing quantum connectivity in quantum computing architectures due to its simple operation and compatibility with industry fabrication.