A surface code quantum computer in silicon.

Area of Science:

• Quantum computing
• Solid-state physics
• Nanotechnology

Background:

• Silicon-based quantum computing offers long coherence times and scalability.
• Topological quantum error correction requires 2D qubit arrays, posing fabrication and control challenges.
• Existing architectures struggle with the complexity of independent qubit control.

Purpose of the Study:

• To present a novel architecture for scalable quantum information processing in silicon.
• To address the challenges of fabricating and controlling 2D qubit arrays for quantum error correction.
• To leverage the uniformity of phosphorus donor nuclear spin qubits for efficient control.

Main Methods:

• A shared-control paradigm utilizing a 2D lattice of phosphorus donor qubits.
• A crisscross gate array architecture with vertically separated control layers.
• Global spin control for activating multiple qubits in parallel for surface code operations.

Main Results:

• The proposed architecture simplifies control by avoiding independent qubit manipulation and complex interconnects.
• Simulated quantum operations are demonstrated to be below the surface code error threshold.
• The design is compatible with demonstrated fabrication and control techniques.

Conclusions:

• The architecture offers a new pathway for large-scale quantum information processing in silicon.
• The shared-control approach effectively exploits the uniformity of phosphorus donor qubits.
• This design paves the way for building fault-tolerant quantum computers.