Subsystem surface and compass code sensitivities to non-identical infidelity distributions on heavy-hex lattice

• URL: http://arxiv.org/abs/2402.08203v1
• Date: Tue, 13 Feb 2024 04:05:50 GMT
• Title: Subsystem surface and compass code sensitivities to non-identical infidelity distributions on heavy-hex lattice
• Authors: Malcolm S. Carroll, James R. Wootton and Andrew W. Cross
• Abstract summary: We investigate how the logical error rate depends on parameters of the noise distribution for the subsystem surface code and the compass code. The average logical error rate depends on the average of the physical qubit infidelity distribution without sensitivity to higher moments. A decoder that is aware of location specific error rates modestly improves the logical error rate.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Logical qubits encoded into a quantum code exhibit improved error rates when the physical error rates are sufficiently low, below the pseudothreshold. Logical error rates and pseudothresholds can be estimated for specific circuits and noise models, and these estimates provide approximate goals for qubit performance. However, estimates often assume uniform error rates, while real devices have static and/or dynamic distributions of non-identical error rates and may exhibit outliers. These distributions make it more challenging to evaluate, compare, and rank the expected performance of quantum processors. We numerically investigate how the logical error rate depends on parameters of the noise distribution for the subsystem surface code and the compass code on a subdivided hexagonal lattice. Three notable observations are found: (1) the average logical error rate depends on the average of the physical qubit infidelity distribution without sensitivity to higher moments (e.g., variance or outliers) for a wide parameter range; (2) the logical error rate saturates as errors increase at one or a few "bad" locations; and (3) a decoder that is aware of location specific error rates modestly improves the logical error rate. We discuss the implications of these results in the context of several different practical sources of outliers and non-uniform qubit error rates.

Related papers

• Bounds on Autonomous Quantum Error Correction [3.9119979887528125]
  We analyze Markovian autonomous decoders that can be implemented with a wide range of qubit and bosonic error-correcting codes. For many-body quantum codes, we show that, to achieve error suppression comparable to active error correction, autonomous decoders generally require correction rates that grow with code size.
  arXiv  Detail & Related papers  (2023-08-30T18:00:07Z)
• Randomized compiling in fault-tolerant quantum computation [0.0]
  We present an algorithm projecting the state of the system onto a logical state with a well-defined error. The algorithm does not significantly increase the depth of the logical circuit.
  arXiv  Detail & Related papers  (2023-06-23T19:17:34Z)
• Coherent errors and readout errors in the surface code [0.0]
  We consider the combined effect of readout errors and coherent errors on the surface code. We find a threshold for this combination of errors, with an error rate close to the threshold of the corresponding incoherent error channel.
  arXiv  Detail & Related papers  (2023-03-08T15:50:44Z)
• Deep Quantum Error Correction [73.54643419792453]
  Quantum error correction codes (QECC) are a key component for realizing the potential of quantum computing. In this work, we efficiently train novel emphend-to-end deep quantum error decoders. The proposed method demonstrates the power of neural decoders for QECC by achieving state-of-the-art accuracy.
  arXiv  Detail & Related papers  (2023-01-27T08:16:26Z)
• Quantum error correction with dissipatively stabilized squeezed cat qubits [68.8204255655161]
  We propose and analyze the error correction performance of a dissipatively stabilized squeezed cat qubit. We find that for moderate squeezing the bit-flip error rate gets significantly reduced in comparison with the ordinary cat qubit while leaving the phase flip rate unchanged.
  arXiv  Detail & Related papers  (2022-10-24T16:02:20Z)
• Correcting non-independent and non-identically distributed errors with surface codes [0.8039067099377079]
  We develop and investigate the properties of topological surface codes adapted to a known noise structure by Clifford conjugations. We show that the surface code locally tailored to non-uniform single-qubit noise in conjunction with a scalable matching decoder yields an increase in error thresholds and exponential suppression of sub-threshold failure rates.
  arXiv  Detail & Related papers  (2022-08-03T16:21:44Z)
• Suppressing quantum errors by scaling a surface code logical qubit [147.2624260358795]
  We report the measurement of logical qubit performance scaling across multiple code sizes. Our system of superconducting qubits has sufficient performance to overcome the additional errors from increasing qubit number. Results mark the first experimental demonstration where quantum error correction begins to improve performance with increasing qubit number.
  arXiv  Detail & Related papers  (2022-07-13T18:00:02Z)
• Improved decoding of circuit noise and fragile boundaries of tailored surface codes [61.411482146110984]
  We introduce decoders that are both fast and accurate, and can be used with a wide class of quantum error correction codes. Our decoders, named belief-matching and belief-find, exploit all noise information and thereby unlock higher accuracy demonstrations of QEC. We find that the decoders led to a much higher threshold and lower qubit overhead in the tailored surface code with respect to the standard, square surface code.
  arXiv  Detail & Related papers  (2022-03-09T18:48:54Z)
• Error-rate-agnostic decoding of topological stabilizer codes [0.0]
  We develop a decoder that depends on the bias, i.e., the relative probability of phase-flip to bit-flip errors, but is agnostic to error rate. Our decoder is based on counting the number and effective weight of the most likely error chains in each equivalence class of a given syndrome.
  arXiv  Detail & Related papers  (2021-12-03T15:45:12Z)
• SignalNet: A Low Resolution Sinusoid Decomposition and Estimation Network [79.04274563889548]
  We propose SignalNet, a neural network architecture that detects the number of sinusoids and estimates their parameters from quantized in-phase and quadrature samples. We introduce a worst-case learning threshold for comparing the results of our network relative to the underlying data distributions. In simulation, we find that our algorithm is always able to surpass the threshold for three-bit data but often cannot exceed the threshold for one-bit data.
  arXiv  Detail & Related papers  (2021-06-10T04:21:20Z)
• Exponential suppression of bit or phase flip errors with repetitive error correction [56.362599585843085]
  State-of-the-art quantum platforms typically have physical error rates near $10-3$. Quantum error correction (QEC) promises to bridge this divide by distributing quantum logical information across many physical qubits. We implement 1D repetition codes embedded in a 2D grid of superconducting qubits which demonstrate exponential suppression of bit or phase-flip errors.
  arXiv  Detail & Related papers  (2021-02-11T17:11:20Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.