Si/SiGe QuBus for single electron information-processing devices with memory and micron-scale connectivity function

Abstract

The connectivity within single carrier information-processing devices requires transport and storage of single charge quanta. Single electrons have been adiabatically transported while confined to a moving quantum dot in short, all-electrical Si/SiGe shuttle device, called quantum bus (QuBus). Here we show a QuBus spanning a length of 10 μm and operated by only six simply-tunable voltage pulses. We introduce a characterization method, called shuttle-tomography, to benchmark the potential imperfections and local shuttle-fidelity of the QuBus. The fidelity of the single-electron shuttle across the full device and back (a total distance of 19 μm) is (99.7 ± 0.3) %. Using the QuBus, we position and detect up to 34 electrons and initialize a register of 34 quantum dots with arbitrarily chosen patterns of zero and single-electrons. The simple operation signals, compatibility with industry fabrication and low spin-environment-interaction in 28Si/SiGe, promises long-range spin-conserving transport of spin qubits for quantum connectivity in quantum computing architectures. Electron spin qubits in SiGe dots have emerged as promising candidates for quantum information processing. Here the authors demonstrate conveyor-mode single electron shuttling in a Si/SiGe quantum dot device spanning the length of 10 micrometres and operated with a small number of controls