SWAP Gate for Spin Qubits Based on Silicon Devices Integrated with a Micromagnet.

Area of Science:

• Quantum Computing
• Quantum Information Science
• Solid-State Physics

Background:

• SWAP-family gates are essential for quantum information processing, enabling spin state transfer and entanglement.
• Implementing high-fidelity SWAP gates is challenging due to the need for precise control over exchange coupling and energy differences.

Purpose of the Study:

• To demonstrate a high-fidelity SWAP gate in a double quantum dot system.
• To overcome obstacles in achieving adjustable exchange coupling for improved gate fidelity.

Main Methods:

• Utilized a double quantum dot in isotopically enriched silicon with a micromagnet.
• Achieved a two-orders-of-magnitude adjustable ratio between exchange coupling (J) and Zeeman energy difference (ΔE).
• Calibrated single-qubit local phases and analyzed dominant error sources.

Main Results:

• Successfully demonstrated a SWAP gate in the silicon spin qubit system.
• Achieved a significant adjustable ratio between exchange coupling and Zeeman energy difference, enhancing gate fidelity.
• Evaluated the logical-basis fidelity of the SWAP gate.

Conclusions:

• The demonstrated SWAP gate is a significant step towards high-fidelity quantum operations.
• This work paves the way for advanced quantum communication on chip and quantum simulation.
• The developed techniques are crucial for scalable quantum computing architectures.