Resonantly Driven Singlet-Triplet Spin Qubit in Silicon

Area of Science:

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

Background:

• Singlet-triplet spin qubits are promising candidates for quantum computation.
• Achieving high fidelity and long coherence times is crucial for scalable quantum computers.
• Silicon offers a promising platform due to its mature fabrication technology.

Purpose of the Study:

• To implement and characterize a resonantly driven singlet-triplet spin qubit in silicon.
• To demonstrate universal quantum control over the qubit.
• To achieve high single-gate fidelity and long coherence times.

Main Methods:

• Implementation of a two-electron singlet-triplet spin qubit in silicon.
• Utilizing resonant drive of the exchange interaction for qubit control.
• Employing randomized benchmarking to assess gate fidelity.
• Leveraging a large micromagnet Zeeman field gradient for reduced charge noise.

Main Results:

• Demonstrated a resonantly driven singlet-triplet spin qubit in silicon.
• Achieved a qubit coherence time (T_{2}^{*}) exceeding 1 μs, limited by nuclear spin dephasing.
• Obtained a single-gate fidelity of 99.6% via randomized benchmarking.
• This represents the highest fidelity reported for singlet-triplet qubits to date.

Conclusions:

• The implemented silicon singlet-triplet qubit shows excellent performance with high fidelity and long coherence.
• Resonant drive provides effective universal quantum control.
• Silicon is a viable platform for high-fidelity spin qubits, paving the way for quantum computing.