Coherent spin qubit transport in silicon.

Area of Science:

• Quantum computing
• Solid-state physics
• Quantum information science

Background:

• Scalable quantum processors require efficient qubit connectivity.
• Current architectures with nearest-neighbor interactions incur significant qubit overheads.
• Coherent qubit transport offers a solution for enhanced connectivity.

Purpose of the Study:

• To demonstrate high-fidelity coherent transport of electron spin qubits.
• To assess the impact of qubit transport on qubit fidelity.
• To provide elements for on-chip quantum information distribution.

Main Methods:

• Utilizing isotopically-enriched silicon for quantum dot fabrication.
• Implementing Ramsey interferometry and quantum state tomography.
• Observing qubit precession in the inter-site tunneling regime.

Main Results:

• Achieved a polarization transfer fidelity of 99.97%.
• Reported an average coherent transfer fidelity of 99.4%.
• Demonstrated key elements for high-fidelity qubit transport.

Conclusions:

• Coherent qubit transport in silicon is feasible with high fidelity.
• This technique reinforces the scaling prospects of silicon-based spin qubits.
• Enables high-fidelity, on-chip quantum information distribution.