Quantum-dot-based resonant exchange qubit.

Area of Science:

• Quantum computing
• Solid-state physics
• Electron spin qubits

Background:

• Quantum bits (qubits) are fundamental to quantum computation.
• Controlling qubit states rapidly and with high fidelity is crucial for building quantum computers.
• Solid-state systems offer scalability for quantum hardware.

Purpose of the Study:

• To introduce a new solid-state qubit architecture.
• To demonstrate rapid and full qubit control using exchange interactions.
• To investigate qubit performance metrics like gate times and coherence.

Main Methods:

• Utilizing exchange interactions between confined electrons for qubit control.
• Employing radio-frequency (rf) gate-voltage pulses for manipulation.
• Operating at a detuning sweet spot to minimize leakage.
• Measuring qubit performance using multipulse echo techniques.

Main Results:

• Achieved two-axis qubit control.
• Demonstrated a π/2-gate time of 2.5 nanoseconds.
• Obtained a coherence time of 19 microseconds.
• Suppressed leakage errors via a large exchange gap at the sweet spot.

Conclusions:

• The developed solid-state qubit offers rapid and precise control.
• The qubit architecture shows promise for high-fidelity quantum operations.
• Experimental results align well with theoretical predictions, including hyperfine noise effects.