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Related papers: Fault-Tolerance of "Bad" Quantum Low-Density Parit…

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We propose a fault-tolerant quantum computation scheme that is broadly applicable to quantum low-density parity-check (qLDPC) codes. The scheme achieves constant qubit overhead and a time overhead of $O(d^{a+o(1)})$ for any $[[n,k,d]]$…

Quantum Physics · Physics 2026-04-14 Guo Zhang , Yuanye Zhu , Ying Li

We study approximate quantum low-density parity-check (QLDPC) codes, which are approximate quantum error-correcting codes specified as the ground space of a frustration-free local Hamiltonian, whose terms do not necessarily commute. Such…

Quantum Physics · Physics 2020-11-13 Thomas C. Bohdanowicz , Elizabeth Crosson , Chinmay Nirkhe , Henry Yuen

Density evolution for protograph Low-Density Parity-Check (LDPC) codes is considered, and it is shown that the message-error rate falls double-exponentially with iterations whenever the degree-2 subgraph of the protograph is cycle-free and…

Information Theory · Computer Science 2016-11-18 Asit Kumar Pradhan , Andrew Thangaraj , Arunkumar Subramanian

Phases of matter with robust ground-state degeneracy, such as the quantum toric code, are known to be capable of robust quantum information storage. Here, we address the converse question: given a quantum error correcting code, when does it…

Quantum Physics · Physics 2025-08-21 Chao Yin , Andrew Lucas

Iterative decoders used for decoding low-density parity-check (LDPC) and moderate-density parity-check (MDPC) codes are not characterized by a deterministic decoding radius and their error rate performance is usually assessed through…

Information Theory · Computer Science 2020-02-27 Paolo Santini , Massimo Battaglioni , Marco Baldi , Franco Chiaraluce

Quantum error correction is the building block for constructing fault-tolerant quantum processors that can operate reliably even if its constituting elements are corrupted by decoherence. In this context, real-time decoding is a necessity…

Quantum Physics · Physics 2024-02-15 Antonio deMarti iOlius , Josu Etxezarreta Martinez

Quantum error correction is an important building block for reliable quantum information processing. A challenging hurdle in the theory of quantum error correction is that it is significantly more difficult to design error-correcting codes…

Quantum Physics · Physics 2015-03-17 Yuichiro Fujiwara , Alexander Gruner , Peter Vandendriessche

The preparation of a quantum state using a noisy quantum computer (gate noise strength $\delta$), will necessarily affect an O($\delta$)-fraction of the qubits, no matter which protocol is used. Here, we show that fault-tolerant quantum…

Quantum Physics · Physics 2026-02-20 Matthias Christandl , Omar Fawzi , Ashutosh Goswami

Low-density parity check (LDPC) codes are a significant class of classical codes with many applications. Several good LDPC codes have been constructed using random, algebraic, and finite geometries approaches, with containing cycles of…

Quantum Physics · Physics 2016-11-18 Salah A. Aly

We show that belief propagation combined with ordered statistics post-processing is a general decoder for quantum low density parity check codes constructed from the hypergraph product. To this end, we run numerical simulations of the…

Quantum Physics · Physics 2021-01-04 Joschka Roffe , David R. White , Simon Burton , Earl T. Campbell

In efforts to scale the size of quantum computers, modularity plays a central role across most quantum computing technologies. In the light of fault tolerance, this necessitates designing quantum error-correcting codes that are compatible…

Quantum Physics · Physics 2023-05-16 Armands Strikis , Lucas Berent

Quantum low-density parity-check (qLDPC) codes are quantum stabilizer codes where each stabilizer acts on a constant number of qubits and each qubit is acted on by a constant number of stabilizers. We study qLDPC codes constructed from…

Quantum Physics · Physics 2022-03-08 Ting-Chun Lin , Min-Hsiu Hsieh

In this paper, a construction of a pair of "regular" quasi-cyclic LDPC codes as ingredient codes for a quantum error-correcting code is proposed. That is, we find quantum regular LDPC codes with various weight distributions. Furthermore our…

Quantum Physics · Physics 2016-11-18 Manabu Hagiwara , Hideki Imai

The speed at which two remote parties can exchange secret keys over a fixed-length fiber-optic cable in continuous-variable quantum key distribution (CV-QKD) is currently limited by the computational complexity of post-processing algorithms…

Quantum Physics · Physics 2019-05-28 Mario Milicevic , Chen Feng , Lei M. Zhang , P. Glenn Gulak

Quantum codes with low-weight stabilizers known as LDPC codes have been actively studied recently due to their simple syndrome readout circuits and potential applications in fault-tolerant quantum computing. However, all families of quantum…

Quantum Physics · Physics 2014-10-20 Sergey Bravyi , Matthew B. Hastings

Fault-tolerant quantum computation critically depends on architectures uniting high encoding rates with physical implementability. Quantum low-density parity-check (qLDPC) codes, including bivariate bicycle (BB) codes, achieve dramatic…

Quantum Physics · Physics 2025-06-24 Yingli Yang , Guo Zhang , Ying Li

Quantum error correction becomes a practical possibility only if the physical error rate is below a threshold value that depends on a particular quantum code, syndrome measurement circuit, and decoding algorithm. Here we present an…

Quantum low-density parity-check (QLDPC) codes provide a practical balance between error-correction capability and implementation complexity in quantum error correction (QEC). In this paper, we propose an algebraic construction based on…

Information Theory · Computer Science 2026-01-14 Alessio Baldelli , Massimo Battaglioni , Jonathan Mandelbaum , Sisi Miao , Laurent Schmalen

Quantum Error Correction (QEC) is an essential field of research towards the realization of large-scale quantum computers. On the theoretical side, a lot of effort is put into designing error-correcting codes that protect quantum data from…

Quantum Physics · Physics 2023-02-10 Lucas Berent , Lukas Burgholzer , Robert Wille

Quantum error correction plays a prominent role in the realization of quantum computation, and quantum low-density parity-check (qLDPC) codes are believed to be practically useful stabilizer codes. While qLDPC codes are defined to have…

Quantum Physics · Physics 2025-10-29 Shi Jie Samuel Tan , Lev Stambler