## Abstract

A quantum computer needs the assistance of a classical algorithm to detect and identify errors that affect encoded quantum information. At this interface of classical and quantum computing the technique of machine learning has appeared as a way to tailor such an algorithm to the specific error processes of an experiment - without the need for a priori knowledge of the error model. Here, we apply this technique to topological color codes. We demonstrate that a recurrent neural network with long short-term memory cells can be trained to reduce the error rate
_{L}
of the encoded logical qubit to values much below the error rate
_{phys}
of the physical qubits - fitting the expected power law scaling , with d the code distance. The neural network incorporates the information from 'flag qubits' to avoid reduction in the effective code distance caused by the circuit. As a test, we apply the neural network decoder to a density-matrix based simulation of a superconducting quantum computer, demonstrating that the logical qubit has a longer life-time than the constituting physical qubits with near-term experimental parameters.

Original language | English |
---|---|

Article number | 013003 |

Number of pages | 13 |

Journal | New Journal of Physics |

Volume | 21 |

Issue number | 1 |

DOIs | |

Publication status | Published - 8 Jan 2019 |

## Keywords

- machine learning
- quantum error correction
- recurrent neural network
- topological color codes