Gate-based single-shot readout of spins in silicon

Anderson West, Bas Hensen, Alexis Jouan, Tuomo Tanttu, Chih-Hwan Yang, Alessandro Rossi, M. Fernando Gonzalez-Zalba, Fay Hudson, Andrea Morello, David J. Reilly, Andrew S. Dzurak

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Abstract

Electron spins in silicon quantum dots provide a promising route towards realizing the large number of coupled qubits required for a useful quantum processor 1–7 . For the implementation of quantum algorithms and error detection 8–10 , qubit measurements are ideally performed in a single shot, which is presently achieved using on-chip charge sensors, capacitively coupled to the quantum dots 11 . However, as the number of qubits is increased, this approach becomes impractical due to the footprint and complexity of the charge sensors, combined with the required proximity to the quantum dots 12 . Alternatively, the spin state can be measured directly by detecting the complex impedance of spin-dependent electron tunnelling between quantum dots 13–15 . This can be achieved using radiofrequency reflectometry on a single gate electrode defining the quantum dot itself 15–19 , significantly reducing the gate count and architectural complexity, but thus far it has not been possible to achieve single-shot spin readout using this technique. Here, we detect single electron tunnelling in a double quantum dot and demonstrate that gate-based sensing can be used to read out the electron spin state in a single shot, with an average readout fidelity of 73%. The result demonstrates a key step towards the readout of many spin qubits in parallel, using a compact gate design that will be needed for a large-scale semiconductor quantum processor.

Original languageEnglish
Pages (from-to)437-443
Number of pages7
JournalNature Nanotechnology
Volume14
Issue number5
Early online date11 Mar 2019
DOIs
Publication statusPublished - 31 May 2019

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Keywords

  • nanoscale devices
  • quantum processing
  • quantum dots

Cite this

West, A., Hensen, B., Jouan, A., Tanttu, T., Yang, C-H., Rossi, A., ... Dzurak, A. S. (2019). Gate-based single-shot readout of spins in silicon. Nature Nanotechnology, 14(5), 437-443. https://doi.org/10.1038/s41565-019-0400-7