Coherent spin qubit transport in silicon

Understand

A fault-tolerant quantum processor may be configured using stationary qubits interacting only with their nearest neighbours, but at the cost of significant overheads in physical qubits per logical qubit.

• Such overheads could be reduced by coherently transporting qubits across the chip, allowing connectivity beyond immediate neighbours.
• Here we demonstrate high-fidelity coherent transport of an electron spin qubit between quantum dots in isotopically-enriched silicon.
• We observe qubit precession in the inter-site tunnelling regime and assess the impact of qubit transport using Ramsey interferometry and quantum state tomography techniques.