Optimizing Encoder Circuits of Entanglement-Assisted Quantum LDPC Codes via Beam Search
- URL: http://arxiv.org/abs/2606.11468v1
- Date: Tue, 09 Jun 2026 21:57:07 GMT
- Title: Optimizing Encoder Circuits of Entanglement-Assisted Quantum LDPC Codes via Beam Search
- Abstract summary: Entment-assisted (EA) quantum QC-LDPC codes offer strong error-correction capabilities with structured parity-check matrices.<n>Their practical use depends on efficient encoder circuits and the availability of pre-shared Bell pairs (ebits)
- Score: 6.754749859345508
- License: http://creativecommons.org/licenses/by-nc-nd/4.0/
- Abstract: Entanglement-assisted (EA) quantum QC-LDPC codes offer strong error-correction capabilities with structured parity-check matrices, but their practical use depends on efficient encoder circuits and the availability of pre-shared Bell pairs (ebits). In all encoder implementations based on the stabilizer formalism, the dominant contribution to this complexity comes from the use of controlled gates. In this paper, we adopt the Sharma-Kumar-Garani (SKG) encoder construction. We formulate the encoder optimization as a search over GF(2) row operations that decompose the binary matrix derived from its CNOT sub-sequence. We solve this problem using a beam search algorithm guided by a Hamming-distance heuristic. For the tested EA quantum QC-LDPC code families, the proposed method achieves CNOT-count reductions of 7.3-34.0% relative to the SKG baseline encoder. The optimized circuits also yield lower CNOT counts than Patel-Markov-Hayes synthesis on all tested instances and are verified by stabilizer-tableau simulation. These results show that substantial encoder simplification is possible for structured EA QC-LDPC codes.
Related papers
- Quantum low-density lattice codes [0.0]
Gottesman-Kitaev-Preskill (GKP) codes provide a family of promising schemes for encoding discrete quantum information (qudits) into infinite-dimensional bosonic modes based on mathematical lattices.<n>This paper presents a strategy of co-designing the decoder and the quantum error-correcting code itself by constructing lattices for which decoding is feasible.<n>The relevant source code will be released in open-source Julia packages LatticeDecoder.jl and SymplecticGKP.jl.
arXiv Detail & Related papers (2026-09-02T18:00:19Z) - LDGM-Based Quantum Codes for Fault-Tolerant Quantum Computation [0.0]
We construct a new family of Calderbank-Shor-Steane (CSS) codes using the generator and parity-check matrices of Low-Density Generator Matrix (LDGM) codes.<n>Decoding is performed in an iterative manner, by applying message passing over the associated graph, and discrete Density Evolution (DDE) is used to optimize performance in the depolarizing channel.
arXiv Detail & Related papers (2026-07-16T16:02:16Z) - Noise-Aware Synthesis of Quantum LDPC Encoder Circuits via Two-Sided Hamming Descent [7.519872646378835]
We formulate LDPC encoder preparation as a circuit-resynthesis problem.<n>We seek a lower-cost equivalent circuit that can be routed efficiently on the target hardware.<n>We show that encoder-matrix resynthesis is an effective compiler-level tool for preparing quantum LDPC code states.
arXiv Detail & Related papers (2026-07-05T19:07:48Z) - Synthesis and Optimization of Encoding Circuits for Fault-Tolerant Quantum Computation [4.561664406615985]
We develop methods for synthesizing efficient encoders for arbitrary stabilizer codes.<n>For families with a modular structure, such as tableaud and holographic codes, we show how large encoders can be assembled from optimized local constituent encoders.<n>We obtain improvements of up to 43% in two-qubit gate count and up to 70% in depth.
arXiv Detail & Related papers (2026-05-14T18:00:01Z) - Design and Analysis of Quantum Dual-Containing CSS LDPC Codes based on Quasi-Dyadic Matrices [12.47911764690163]
This paper introduces two constructions of high-rate, quantum dual-containing (DC) Calderbank-Shor-Steane (CSS) low-density parity-check (LDPC) codes.<n>Their DC structure enables the implementation of the Hadamard gate, and, jointly with the sparsity of their parity-check matrices, enable low-complexity decoding.<n>We show that the quantum CSS LDPC codes obtained through these constructions achieve better finite-length error rate performance than existing DC codes across different block lengths and code rates.
arXiv Detail & Related papers (2026-05-05T11:00:37Z) - Threshold Selection for Iterative Decoding of $(v,w)$-regular Binary Codes [84.0257274213152]
Iterative bit flipping decoders are an efficient choice for sparse $(v,w)$-regular codes.<n>We propose concrete criteria for threshold determination, backed by a closed form model.
arXiv Detail & Related papers (2025-01-23T17:38:22Z) - List Decodable Quantum LDPC Codes [49.2205789216734]
We give a construction of Quantum Low-Density Parity Check (QLDPC) codes with near-optimal rate-distance tradeoff.
We get efficiently list decodable QLDPC codes with unique decoders.
arXiv Detail & Related papers (2024-11-06T23:08:55Z) - Decoding Quantum LDPC Codes Using Graph Neural Networks [52.19575718707659]
We propose a novel decoding method for Quantum Low-Density Parity-Check (QLDPC) codes based on Graph Neural Networks (GNNs)
The proposed GNN-based QLDPC decoder exploits the sparse graph structure of QLDPC codes and can be implemented as a message-passing decoding algorithm.
arXiv Detail & Related papers (2024-08-09T16:47:49Z) - Quaternary Neural Belief Propagation Decoding of Quantum LDPC Codes with Overcomplete Check Matrices [45.997444794696676]
Quantum low-density parity-check (QLDPC) codes are promising candidates for error correction in quantum computers.<n>One of the major challenges in implementing QLDPC codes in quantum computers is the lack of a universal decoder.<n>We first propose to decode QLDPC codes with a belief propagation (BP) decoder operating on overcomplete check matrices.<n>We extend the neural BP (NBP) decoder, which was originally studied for suboptimal binary BP decoding of QLPDC codes, to quaternary BP decoders.
arXiv Detail & Related papers (2023-08-16T08:24:06Z) - Single-shot decoding of good quantum LDPC codes [38.12919328528587]
We prove that quantum Tanner codes facilitate single-shot quantum error correction (QEC) of adversarial noise.
We show that in order to suppress errors over multiple repeated rounds of QEC, it suffices to run the parallel decoding algorithm for constant time in each round.
arXiv Detail & Related papers (2023-06-21T18:00:01Z) - Neural Belief Propagation Decoding of Quantum LDPC Codes Using
Overcomplete Check Matrices [60.02503434201552]
We propose to decode QLDPC codes based on a check matrix with redundant rows, generated from linear combinations of the rows in the original check matrix.
This approach yields a significant improvement in decoding performance with the additional advantage of very low decoding latency.
arXiv Detail & Related papers (2022-12-20T13:41:27Z) - Efficient Nearest Neighbor Search for Cross-Encoder Models using Matrix
Factorization [60.91600465922932]
We present an approach that avoids the use of a dual-encoder for retrieval, relying solely on the cross-encoder.
Our approach provides test-time recall-vs-computational cost trade-offs superior to the current widely-used methods.
arXiv Detail & Related papers (2022-10-23T00:32:04Z)
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.