Resonantly driven CNOT gate for electron spins

Area of Science:

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

Background:

• Universal quantum computing relies on high-fidelity single-qubit and two-qubit gates.
• Electron spins in silicon offer a promising platform for qubits, but robust CNOT gates have been hindered by noise.
• Previous efforts faced challenges with nuclear spin dephasing and charge noise, limiting CNOT gate performance.

Purpose of the Study:

• To demonstrate an efficient and high-fidelity CNOT gate for electron spins in silicon.
• To overcome the limitations of nuclear spin dephasing and charge noise in quantum dot architectures.
• To enable the implementation of multi-qubit algorithms in silicon-based quantum processors.

Main Methods:

• Utilized resonantly driven CNOT gate operations on electron spins within a silicon quantum dot device.
• Achieved single-qubit rotations with fidelities exceeding 99%, verified through randomized benchmarking.
• Controlled exchange coupling to implement the quantum CNOT gate with resonant driving in approximately 200 nanoseconds.

Main Results:

• Demonstrated a resonantly driven CNOT gate for electron spins in silicon with high fidelity.
• Achieved single-qubit rotation fidelities greater than 99%.
• Generated a Bell state with 78% fidelity using the implemented CNOT gate, after correcting for state preparation and measurement errors.

Conclusions:

• The developed CNOT gate is an efficient and robust building block for silicon-based quantum computing.
• The quantum dot device architecture facilitates the implementation of multi-qubit algorithms.
• This work represents a significant step towards scalable and fault-tolerant quantum computation in silicon.