High-fidelity single-spin shuttling in silicon

The computational power and fault-tolerance of future large-scale quantumprocessors derive in large part from the connectivity between the qubits. Oneapproach to increase connectivity is to engineer qubit-qubit interactions at adistance. Alternatively, the connectivity can be increased by physicallydisplacing the qubits. This has been explored in trapped-ion experiments andusing neutral atoms trapped with optical tweezers. For semiconductor spinqubits, several studies have investigated spin coherent shuttling of individualelectrons, but high-fidelity transport over extended distances remains to bedemonstrated. Here we report shuttling of an electron inside an isotopicallypurified Si/SiGe heterostructure using electric gate potentials. First, we formstatic quantum dots, and study how spin coherence decays as we repeatedly movea single electron between up to five dots. Next, we create a traveling wavepotential to transport an electron in a moving quantum dot. This second methodshows substantially better spin coherence than the first. It allows us todisplace an electron over an effective distance of 10 μm in under 200 nswith an average fidelity of 99

Further reading#

• Access Paper in arXiv.org