Rapid gate-based spin read-out in silicon using an on-chip resonator

Area of Science:

• Quantum computing
• Solid-state physics
• Nanotechnology

Background:

• Silicon spin qubits are a leading platform for quantum computation.
• Accurate and fast qubit measurement is essential for quantum computation.
• Current charge detection methods hinder scalability.

Purpose of the Study:

• To develop a scalable, on-chip measurement technique for silicon spin qubits.
• To achieve high-fidelity, single-shot read-out of quantum states.
• To simplify quantum computing system architecture.

Main Methods:

• Coupling an on-chip superconducting resonant circuit to gates in a double quantum dot.
• Measuring transmitted power through a feedline to probe charge susceptibility.
• Utilizing Pauli's exclusion principle for spin-to-charge conversion.

Main Results:

• Achieved a signal-to-noise ratio of ~6 within 1 μs integration time.
• Demonstrated single-shot read-out of a two-electron spin state with >98% fidelity in 6 μs.
• Eliminated the need for external electrometers.

Conclusions:

• The developed on-chip resonator enables rapid and high-fidelity qubit measurement.
• This technique simplifies system architecture and is suitable for dense spin qubit arrays.
• The results provide a foundation for frequency-multiplexed read-out in scalable quantum computers.