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Quantum computing

Extra levels give extra functionality

Nature Physics volume 19, page 22 (2023)Cite this article

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The performance of computing devices is determined by the implementation of logical operations at the hardware level. A quantum AND gate designed using three energy levels of a superconducting circuit may speed up quantum computing algorithms.

Logic gates are elementary building blocks of both classical and quantum digital computers. They represent simple computational operations, using classical or quantum bits as inputs and outputs. Unlike their classical counterparts, quantum gates are reversible, meaning that their input can be computed from the output. In its simplest form, the AND gate is irreversible because it consumes two bits of information to produce one output bit. However, it can be made reversible using the so-called Toffoli gate1,2, which avoids erasing any information by writing the output to a third bit. The need for an extra bit, however, creates challenges for scalable quantum computation. Now, writing in Nature Physics, Ji Chu and colleagues have created a quantum AND gate that requires just two superconducting artificial atoms3.

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References

  1. Fedorov, A., Steffen, L., Baur, M., da Silva, M. P. & Wallraff, A. Nature 481, 170–172 (2012).

    Article  ADS  Google Scholar 

  2. Kim, Y. et al. Nat. Phys. 18, 783–788 (2022).

    Article  Google Scholar 

  3. Chu, J. et al. Nat. Phys. https://doi.org/10.1038/s41567-022-01813-7 (2022).

  4. Bullock, S. S. & Brennen, G. K. J. Phys. A: Math. Theor. 40, 3481–3506 (2007).

    Article  ADS  Google Scholar 

  5. Campbell, E. T. Phys. Rev. Lett. 113, 230501 (2014).

    Article  ADS  Google Scholar 

  6. Blok, M. S. et al. Phys. Rev. X 11, 021010 (2021).

    Google Scholar 

  7. Chi, Y. et al. Nat. Commun. 13, 1166 (2022).

    Article  ADS  Google Scholar 

  8. Ringbauer, M. et al. Nat. Phys. 18, 1053–1057 (2022).

    Article  Google Scholar 

Download references

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  1. Google Quantum AI, Venice, CA, USA

    Zhang Jiang

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  1. Zhang Jiang
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Correspondence to Zhang Jiang.

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Jiang, Z. Extra levels give extra functionality. Nat. Phys. 19, 22 (2023). https://doi.org/10.1038/s41567-022-01865-9

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  • DOI: https://doi.org/10.1038/s41567-022-01865-9

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