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Related papers: Transversal non-Clifford gates for quantum LDPC co…

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It is an oft-cited fact that no quantum code can support a set of fault-tolerant logical gates that is both universal and transversal. This no-go theorem is generally responsible for the interest in alternative universality constructions…

Quantum Physics · Physics 2016-09-20 Theodore J. Yoder , Ryuji Takagi , Isaac L. Chuang

We show how to perform scalable fault-tolerant non-Clifford gates in two dimensions by introducing domain walls between the surface code and a non-Abelian topological code whose codespace is stabilized by Clifford operators. We formulate a…

Simulating fermionic systems on qubit-based quantum computers often demands significant computational resources due to the requirement to map fermions to qubits. Thus, designing a fault-tolerant quantum computer that operates directly with…

Quantum Physics · Physics 2026-02-19 Chong-Yuan Xu , Ze-Chuan Liu , Yong Xu

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

We use the recently introduced lifted product to construct a family of Quantum Low Density Parity Check Codes (QLDPC codes). The codes we obtain can be viewed as stacks of surface codes that are interconnected, leading to the name…

Quantum Physics · Physics 2024-08-30 Josias Old , Manuel Rispler , Markus Müller

It is conjectured that quantum computers are able to solve certain problems more quickly than any deterministic or probabilistic computer. A quantum computer exploits the rules of quantum mechanics to speed up computations. However, it is a…

Information Theory · Computer Science 2009-08-15 Salah A. Aly

We introduce a class of 3D color codes, which we call stacked codes, together with a fault-tolerant transformation that will map logical qubits encoded in two-dimensional (2D) color codes into stacked codes and back. The stacked code allows…

Quantum Physics · Physics 2016-03-07 Tomas Jochym-O'Connor , Stephen D. Bartlett

The Clifford hierarchy is a nested sequence of sets of quantum gates that can be fault-tolerantly performed using gate teleportation within standard quantum error correction schemes. The groups of Pauli and Clifford gates constitute the…

Quantum Physics · Physics 2025-01-15 Nadish de Silva , Oscar Lautsch

In pursuit of large-scale fault-tolerant quantum computation, quantum low-density parity-check (LDPC) codes have been established as promising candidates for low-overhead memory when compared to conventional approaches based on surface…

Quantum Physics · Physics 2025-10-28 Zhiyang He , Alexander Cowtan , Dominic J. Williamson , Theodore J. Yoder

We present the Low Density Parity Check (LDPC) forward error correction algorithm adapted for the Quantum Key Distribution (QKD) protocol in a form readily applied by developers. A sparse parity check matrix is required for the LDPC…

Cryptography and Security · Computer Science 2014-04-03 Alan Mink , Anastase Nakassis

We present an entirely 2D transversal realization of phase gates at any level of the Clifford hierarchy, and beyond, using non-Abelian surface codes. Our construction encodes a logical qubit in the quantum double $D(G)$ of a non-Abelian…

Quantum Physics · Physics 2026-01-19 Alison Warman , Sakura Schafer-Nameki

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

We present a general framework for the construction of quantum tensor product codes (QTPC). In a classical tensor product code (TPC), its parity check matrix is con- structed via the tensor product of parity check matrices of the two…

Quantum Physics · Physics 2017-10-26 Jihao Fan , Yonghui Li , Min-Hsiu Hsieh , Hanwu Chen

Quasi-cyclic (QC) low-density parity-check (LDPC) codes are a class of LDPC codes with a simple construction facilitating hardware implementation while achieving excellent performance. In this paper, we introduce an algorithm that…

Information Theory · Computer Science 2025-07-15 Haizheng Li , Sisi Miao , Laurent Schmalen

Fault tolerance in quantum protocols requires contributions from error-correcting codes and their suitable decoders. Quantum Low-Density Parity Check (QLDPC) codes are one of the most explored quantum codes that have good coding rate and…

Quantum Physics · Physics 2026-04-24 Mainak Bhattacharyya , Ankur Raina

While low-density parity-check (LDPC) codes are near capacity-achieving when paired with iterative decoders, these decoders may not output a codeword due to the existence of pseudocodewords. Thus, pseudocodewords have been studied to give…

Information Theory · Computer Science 2025-12-03 Wittawat Kositwattanarerk , Gretchen L. Matthews , Emily McMillon , Tunchanok Yutitumsatit

Quantum low-density parity-check (LDPC) codes are a promising avenue to reduce the cost of constructing scalable quantum circuits. However, it is unclear how to implement these codes in practice. Seminal results of Bravyi & Terhal, and…

Quantum Physics · Physics 2022-08-17 Nouédyn Baspin , Anirudh Krishna

Quantum LDPC codes may provide a path to build low-overhead fault-tolerant quantum computers. However, as general LDPC codes lack geometric constraints, na\"ive layouts couple many distant qubits with crossing connections which could be…

Quantum Physics · Physics 2022-08-17 Maxime A. Tremblay , Nicolas Delfosse , Michael E. Beverland

We introduce Decision Tree Decoders (DTDs), which rely only on the sparsity of the binary check matrix, making them broadly applicable for decoding any quantum low-density parity-check (qLDPC) code and fault-tolerant quantum circuits. DTDs…

Quantum Physics · Physics 2025-02-25 Kai R. Ott , Bence Hetényi , Michael E. Beverland

In fault-tolerant quantum computing with the surface code, non-Clifford gates are crucial for universal computation. However, implementing these gates using methods like magic state distillation and code switching requires significant…

Quantum Physics · Physics 2025-07-02 Sheng-Jie Huang , Yanzhu Chen