High-fidelity single-spin shuttling in silicon

Abstract

The computational power and fault-tolerance of future large-scale quantum processors derive in large part from the connectivity between the qubits. One approach to increase connectivity is to engineer qubit-qubit interactions at a distance. Alternatively, the connectivity can be increased by physically displacing the qubits. This has been explored in trapped-ion experiments and using neutral atoms trapped with optical tweezers. For semiconductor spin qubits, several studies have investigated spin coherent shuttling of individual electrons, but high-fidelity transport over extended distances remains to be demonstrated. Here we report shuttling of an electron inside an isotopically purified Si/SiGe heterostructure using electric gate potentials. First, we form static quantum dots, and study how spin coherence decays as we repeatedly move a single electron between up to five dots. Next, we create a traveling wave potential to transport an electron in a moving quantum dot. This second method shows substantially better spin coherence than the first. It allows us to displace an electron over an effective distance of 10 $\mu$m in under 200 ns with an average fidelity of 99.5%. These results will guide future efforts to realize large-scale semiconductor quantum processors, making use of electron shuttling both within and between qubit arrays.

15 pages, 15 figures

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Cited by in corpus (15)

• Industrially fabricated single-electron quantum dots in Si/Si-Ge heterostructures
• Hands-on Introduction to Randomized Benchmarking
• Erasure conversion for singlet-triplet spin qubits enables high-performance shuttling-based quantum error correction
• Suppressing Si Valley Excitation and Valley-Induced Spin Dephasing for Long-Distance Shuttling
• Pursuing high-fidelity control of spin qubits in natural Si/SiGe quantum dot
• Interplay of Zeeman Splitting and Tunnel Coupling in Coherent Spin Qubit Shuttling
• Electrical Interconnects for Silicon Spin Qubits
• Omnidirectional shuttling to avoid valley excitations in Si/SiGe quantum wells
• Rapid Autotuning of a SiGe Quantum Dot into the Single-Electron Regime with Machine Learning and RF-Reflectometry FPGA-Based Measurements
• Highly Tunable Two-Qubit Interactions in Si/SiGe Quantum Dots by Interchanging the Roles of Qubit-Defining Gates
• Comparison of spin-qubit architectures for quantum error-correcting codes
• Numerical simulation of coherent spin-shuttling in a QuBus with charged defects
• Coupling a ${}^{73}$Ge nuclear spin to an electrostatically defined quantum dot
• Spin qubit shuttling between coupled quantum dots with inhomogeneous Landé g-tensors
• Digital-Controlled Method of Conveyor-Belt Spin Shuttling in Silicon for Large-Scale Quantum Computation