Parallel window decoding enables scalable fault tolerant quantum computation
Abstract Large-scale quantum computers have the potential to hold computational capabilities beyond conventional computers. However, the physical qubits are prone to noise which must be corrected in order to perform fault-tolerant quantum computations. Quantum Error Correction (QEC) provides the pat...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-11-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-023-42482-1 |
| _version_ | 1797636860373106688 |
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| author | Luka Skoric Dan E. Browne Kenton M. Barnes Neil I. Gillespie Earl T. Campbell |
| author_facet | Luka Skoric Dan E. Browne Kenton M. Barnes Neil I. Gillespie Earl T. Campbell |
| author_sort | Luka Skoric |
| collection | DOAJ |
| description | Abstract Large-scale quantum computers have the potential to hold computational capabilities beyond conventional computers. However, the physical qubits are prone to noise which must be corrected in order to perform fault-tolerant quantum computations. Quantum Error Correction (QEC) provides the path for realizing such computations. QEC generates a continuous stream of data that decoders must process at the rate it is received, which can be as fast as 1 μs per QEC round in superconducting quantum computers. If the decoder infrastructure cannot keep up, a data backlog problem is encountered and the computation runs exponentially slower. Today’s leading approaches to quantum error correction are not scalable as existing decoders typically run slower as the problem size is increased, inevitably hitting the backlog problem. Here, we show how to parallelize decoding to achieve almost arbitrary speed, removing this roadblock to scalability. Our parallelization requires some classical feed forward decisions to be delayed, slowing-down the logical clock speed. However, the slow-down is now only polynomial in the size of the QEC code, averting the exponential slowdown. We numerically demonstrate our parallel decoder for the surface code, showing no noticeable reduction in logical fidelity compared to previous decoders and demonstrating the predicted speedup. |
| first_indexed | 2024-03-11T12:40:13Z |
| format | Article |
| id | doaj.art-fe534eed8b51446f8cf3c1746975769f |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-03-11T12:40:13Z |
| publishDate | 2023-11-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-fe534eed8b51446f8cf3c1746975769f2023-11-05T12:22:08ZengNature PortfolioNature Communications2041-17232023-11-011411810.1038/s41467-023-42482-1Parallel window decoding enables scalable fault tolerant quantum computationLuka Skoric0Dan E. Browne1Kenton M. Barnes2Neil I. Gillespie3Earl T. Campbell4RiverlaneRiverlaneRiverlaneRiverlaneRiverlaneAbstract Large-scale quantum computers have the potential to hold computational capabilities beyond conventional computers. However, the physical qubits are prone to noise which must be corrected in order to perform fault-tolerant quantum computations. Quantum Error Correction (QEC) provides the path for realizing such computations. QEC generates a continuous stream of data that decoders must process at the rate it is received, which can be as fast as 1 μs per QEC round in superconducting quantum computers. If the decoder infrastructure cannot keep up, a data backlog problem is encountered and the computation runs exponentially slower. Today’s leading approaches to quantum error correction are not scalable as existing decoders typically run slower as the problem size is increased, inevitably hitting the backlog problem. Here, we show how to parallelize decoding to achieve almost arbitrary speed, removing this roadblock to scalability. Our parallelization requires some classical feed forward decisions to be delayed, slowing-down the logical clock speed. However, the slow-down is now only polynomial in the size of the QEC code, averting the exponential slowdown. We numerically demonstrate our parallel decoder for the surface code, showing no noticeable reduction in logical fidelity compared to previous decoders and demonstrating the predicted speedup.https://doi.org/10.1038/s41467-023-42482-1 |
| spellingShingle | Luka Skoric Dan E. Browne Kenton M. Barnes Neil I. Gillespie Earl T. Campbell Parallel window decoding enables scalable fault tolerant quantum computation Nature Communications |
| title | Parallel window decoding enables scalable fault tolerant quantum computation |
| title_full | Parallel window decoding enables scalable fault tolerant quantum computation |
| title_fullStr | Parallel window decoding enables scalable fault tolerant quantum computation |
| title_full_unstemmed | Parallel window decoding enables scalable fault tolerant quantum computation |
| title_short | Parallel window decoding enables scalable fault tolerant quantum computation |
| title_sort | parallel window decoding enables scalable fault tolerant quantum computation |
| url | https://doi.org/10.1038/s41467-023-42482-1 |
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