Operating semiconductor quantum processors with hopping spins

Area of Science:

• Quantum Computing
• Solid-State Physics

Background:

• Efficient qubit control is crucial for scalable quantum hardware.
• Current resonant control methods face scalability challenges due to signal integration, cross-talk, and heating.

Purpose of the Study:

• To demonstrate a novel quantum control method using engineered spin hopping between quantum dots.
• To achieve high-fidelity quantum gates and explore the potential for quantum error correction.

Main Methods:

• Engineered spin hopping between quantum dots with site-dependent spin quantization axes.
• Demonstrated hopping-based quantum logic operations.
• Statistically mapped coherence of a 10-quantum dot system to establish hopping spins as a tuning method.

Main Results:

• Achieved single-qubit gate fidelities of 99.97%.
• Obtained coherent shuttling fidelities of 99.992% per hop.
• Reached a two-qubit gate fidelity of 99.3%, enabling predicted quantum error correction thresholds.

Conclusions:

• Hopping-based quantum control offers a scalable alternative to resonant control.
• Dense quantum dot arrays with sparse occupation are viable for high-connectivity qubit registers.
• This method facilitates efficient quantum information processing and hardware development.