5 citations · 6 across the 21 of their papers we have counts for
27 papers
MacKay-Neal Codes Achieve Capacity under MAP Decoding
Kenta Kasai
Statistical-mechanical analyses predict that MacKay-Neal codes can achieve channel capacity at fixed degrees. We prove this prediction for the uncoupled MN socket ense…
Low-Weight Canonical Logical Bases from Pair-Partition Codes
Koki Okada, Kenta Kasai
We construct complete canonical logical bases for qubit CSS codes by assigning quaternary coefficients to binary circulant permutation matrix pair-partition (CPM-PP) checks, constr…
Design Principles for Ultra-High-Rate Quantum Codes
Jong Yeon Lee, Koki Okada, Nishad Maskara +2
Reducing the qubit overhead of quantum error correction is a central challenge for scalable fault-tolerant quantum computing. Recent ultra-high-rate quantum codes offer a promising…
Spatially Coupled MacKay-Neal Codes on Symmetric Markov Noise: A Reduction to BMS Channels
Kenta Kasai
We prove a capacity criterion for fixed-degree spatially coupled MacKay--Neal codes on additive symmetric Markov noise. The noise bit flips with probability , so the channel has…
Threshold Saturation from a Bounded Region in Multidimensional Spatially Coupled Codes over the BEC
Kenta Kasai
We prove that a bounded shortened region initiates decoding throughout multidimensional spatially coupled regular LDPC and MacKay--Neal (MN) codes over the binary erasure channel (…
CPM-LDPC Codes Attaining the Minimum-Distance Bound
Kenta Kasai
We study binary quasi-cyclic LDPC codes whose parity-check matrices are full arrays of single circulant permutation matrices (CPMs), referred to here as CPM-LDPC codes. Their minim…
Spatially Coupled MacKay-Neal Codes Achieve Capacity on BMS Channels at Fixed Degrees
Kenta Kasai
We establish two degree-dependent results for spatially coupled MacKay-Neal codes on binary-input memoryless symmetric channels. The ensembles use uniform random smoothing and shor…
Pair-Partition Constructions for CPM-Based Quantum LDPC Codes
Koki Okada, Kenta Kasai
We introduce the pair-partition (PP) construction of binary Calderbank--Shor--Steane quantum low-density parity-check codes from circulant permutation matrices. A square array of p…
Spatially Coupled MacKay-Neal/Hsu-Anastasopoulos CSS Codes Achieve the Quantum-Erasure Hashing Bound by Seeded BP Decoding
Kenta Kasai
We study hard-erasure belief-propagation (BP), understood as the sum-product algorithm on erasure messages, for a punctured MacKay-Neal/Hsu-Anastasopoulos (MN/HA) representation of…
Rate-2/3 Girth-8 (3,18)-Regular Quantum LDPC Codes from Two-Branch Finite-Field Bases and CPM Lifts
Koki Okada, Kenta Kasai
We construct a rate- quantum low-density parity-check (LDPC) code from a -regular two-branch finite-field base and a circulant-permutation-matrix (CPM) lift of degree…
A Factor-Graph Formulation of CSS Syndrome Decoding: Joint BP and Four-State BP
Kenta Kasai
For CSS syndrome decoding, the two check matrices impose binary parity-check constraints on the two Pauli error components. The posterior can therefore be written as a binary facto…
A Two-Branch Finite-Field Construction for Regular CSS LDPC Bases
Koki Okada, Kenta Kasai
This paper develops a two-branch multiplicative-coset construction for regular Calderbank--Shor--Steane (CSS) quantum low-density parity-check base matrices. For a target column we…
Heuristic Search for Minimum-Distance Upper-Bound Witnesses in Quantum APM-LDPC Codes
Kenta Kasai
This paper investigates certified upper bounds on the minimum distance of an explicit family of Calderbank-Shor-Steane quantum LDPC codes constructed from affine permutation matric…
Cross-Commuting Nonabelian Squares in Affine Groups over Finite Commutative Principal Ideal Rings
Kenta Kasai
We study a commutation pattern in which two affine families commute completely across the two families while each family retains internal noncommutativity. For one-dimensional affi…
Finite-Degree Quantum LDPC Codes Reaching the Gilbert-Varshamov Bound
Kenta Kasai
We construct asymptotically good nested Calderbank-Shor-Steane (CSS) code pairs from Hsu-Anastasopoulos codes and MacKay-Neal codes. For fixed balanced triples with even component…
High-Girth Regular Quantum LDPC Codes from Square-Base Hypergraph Products via CPM Lifts
Koki Okada, Kenta Kasai
We study square-base Calderbank--Shor--Steane (CSS) hypergraph-product codes as a finite-length class for regular high-girth quantum low-density parity-check (LDPC) design. For bas…
High-Girth Regular Quantum LDPC Codes from Affine-Coset Structures
Koki Okada, Kenta Kasai
We construct a quantum low-density parity-check code family from a length- Calderbank--Shor--Steane base matrix pair. The base pair is permutation-equivalent to the known SPC(…
Breaking the Orthogonality Barrier in Quantum LDPC Codes
Kenta Kasai
Classical low-density parity-check (LDPC) codes are a widely deployed and well-established technology, forming the backbone of modern communication and storage systems. It is well…
Random Construction of Quantum LDPC Codes
Koki Okada, Kenta Kasai
We propose a method for modifying orthogonal sparse matrix pairs used in CSS codes while preserving their matrix row and column weight distributions, which play a crucial role in d…
Systematic Non-Binary Extension of LDPC-CSS Codes Preserving Orthogonality
Kenta Kasai
We study finite-field extensions that preserve the same support as the parity-check matrices defining a given binary CSS code. Here, an LDPC-CSS code refers to a CSS code whose par…
Sharp Error-Rate Transitions in Quantum QC-LDPC Codes under Joint BP Decoding
Daiki Komoto, Kenta Kasai
In this study, we report that quantum quasi-cyclic low-density parity-check codes decoded via joint belief propagation (BP) exhibit steep error-rate curves, despite the presence of…
Quantum Error Correction Exploiting Degeneracy to Approach the Hashing Bound
Kenta Kasai
Quantum error correction is essential for realizing scalable quantum computation. Among various approaches, low-density parity-check codes over higher-order Galois fields have show…
Quantum Error Correction with Girth-16 Non-Binary LDPC Codes via Affine Permutation Construction
Kenta Kasai
We propose a method for constructing quantum error-correcting codes based on non-binary low-density parity-check codes with Tanner graph girth 16. While conventional constructions…
Efficient Mitigation of Error Floors in Quantum Error Correction using Non-Binary Low-Density Parity-Check Codes
Kenta Kasai
In this paper, we propose an efficient method to reduce error floors in quantum error correction using non-binary low-density parity-check (LDPC) codes. We identify and classify cy…