Fault-Tolerant Belief Propagation for Practical Quantum Memory

• URL: http://arxiv.org/abs/2409.18689v1
• Date: Fri, 27 Sep 2024 12:21:45 GMT
• Title: Fault-Tolerant Belief Propagation for Practical Quantum Memory
• Authors: Kao-Yueh Kuo, Ching-Yi Lai,
• Abstract summary: A fault-tolerant approach to reliable quantum memory is essential for scalable quantum computing. We propose a decoder that utilizes a space-time Tanner graph across multiple rounds of syndrome extraction with mixed-alphabet error variables. Our simulations demonstrate high error thresholds of 0.4%-0.87% and strong error-floor performance for topological code families.
• Score: 6.322831694506286
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: A fault-tolerant approach to reliable quantum memory is essential for scalable quantum computing, as physical qubits are susceptible to noise. Quantum error correction (QEC) must be continuously performed to prolong the memory lifetime. In QEC, error syndromes are generated rapidly, often within the execution time of a few quantum gates, requiring decoders to process this error data with equal speed. A typical QEC cycle involves multiple rounds of syndrome measurements, causing potential error locations to scale rapidly with the code size and the number of measurement rounds. However, no such decoders currently exist for general quantum low-density parity-check codes. In this paper, we propose a fault-tolerant belief propagation (FTBP) decoder that utilizes a space-time Tanner graph across multiple rounds of syndrome extraction with mixed-alphabet error variables. To enhance FTBP, we introduce a technique of probabilistic error consolidation to mitigate degeneracy effects and short cycles. Additionally, we propose an adaptive sliding window procedure that captures long error events across window boundaries and adjusts the decoding in real time. Our simulations demonstrate high error thresholds of 0.4%-0.87% and strong error-floor performance for topological code families, including rotated toric, toric color, and twisted XZZX toric codes.

Related papers

• Degenerate quantum erasure decoding [7.6119527195998025]
  We show how to achieve near-capacity performance with explicit codes and efficient decoders. We furthermore explore the potential of our decoders to handle other error models, such as mixed erasure and depolarizing errors.
  arXiv  Detail & Related papers  (2024-11-20T18:02:05Z)
• Demonstrating real-time and low-latency quantum error correction with superconducting qubits [52.08698178354922]
  We demonstrate low-latency feedback with a scalable FPGA decoder integrated into a superconducting quantum processor. We observe logical error suppression as the number of decoding rounds is increased. The decoder throughput and latency developed in this work, combined with continued device improvements, unlock the next generation of experiments.
  arXiv  Detail & Related papers  (2024-10-07T17:07:18Z)
• Algorithmic Fault Tolerance for Fast Quantum Computing [37.448838730002905]
  We show that fault-tolerant logical operations can be performed with constant time overhead for a broad class of quantum codes. We prove that the deviation from the ideal measurement result distribution can be made exponentially small in the code distance. Our work sheds new light on the theory of fault tolerance, potentially reducing the space-time cost of practical fault-tolerant quantum computation by orders of magnitude.
  arXiv  Detail & Related papers  (2024-06-25T15:43:25Z)
• Analysis of Maximum Threshold and Quantum Security for Fault-Tolerant Encoding and Decoding Scheme Base on Steane Code [10.853582091917236]
  The original Steane code is not fault-tolerant because the CNOT gates in an encoded block may cause error propagation. We first propose a fault-tolerant encoding and decoding scheme, which analyzes all possible errors caused by each quantum gate in an error-correction period. We then provide the fault-tolerant scheme of the universal quantum gate set, including fault-tolerant preparation and verification of ancillary states.
  arXiv  Detail & Related papers  (2024-03-07T07:46:03Z)
• 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)
• Overcoming leakage in scalable quantum error correction [128.39402546769284]
  Leakage of quantum information out of computational states into higher energy states represents a major challenge in the pursuit of quantum error correction (QEC) Here, we demonstrate the execution of a distance-3 surface code and distance-21 bit-flip code on a Sycamore quantum processor where leakage is removed from all qubits in each cycle. We report a ten-fold reduction in steady-state leakage population on the data qubits encoding the logical state and an average leakage population of less than $1 times 10-3$ throughout the entire device.
  arXiv  Detail & Related papers  (2022-11-09T07:54:35Z)
• 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)
• Erasure conversion for fault-tolerant quantum computing in alkaline earth Rydberg atom arrays [3.575043595126111]
  We propose a qubit encoding and gate protocol for $171$Yb neutral atom qubits that converts the dominant physical errors into erasures. We estimate that 98% of errors can be converted into erasures.
  arXiv  Detail & Related papers  (2022-01-10T18:56:31Z)
• Performance of teleportation-based error correction circuits for bosonic codes with noisy measurements [58.720142291102135]
  We analyze the error-correction capabilities of rotation-symmetric codes using a teleportation-based error-correction circuit. We find that with the currently achievable measurement efficiencies in microwave optics, bosonic rotation codes undergo a substantial decrease in their break-even potential.
  arXiv  Detail & Related papers  (2021-08-02T16:12:13Z)
• 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.