Bias-tailored single-shot quantum LDPC codes

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Wu, Shixin, Brun, Todd A., Lidar, Daniel A.
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866912461789069312
author Wu, Shixin
Brun, Todd A.
Lidar, Daniel A.
author_facet Wu, Shixin
Brun, Todd A.
Lidar, Daniel A.
contents Quantum hardware rarely suffers equal amounts of bit-flip ($X$) and phase-flip ($Z$) errors; one type is often much more common than the other. A code that is ``bias-tailored'' can exploit this imbalance, lowering the fault-tolerance overhead. A complementary idea, called "single-shot" error correction, aims to recover from data errors and noisy measurements in a single round of stabilizer readout, avoiding slow repetition cycles. In this work, we combine these two ideas and build a hierarchy of new quantum codes. The full construction starts from the syndrome-encoded hypergraph product code and then tailors it to the dominant error type. The resulting code keeps the single-shot guarantee for every noise model while boosting the threshold whenever $X$ and $Z$ errors are asymmetric. By removing carefully chosen blocks of stabilizers we obtain two trimmed variants. The first, called the simplified code, cuts the physical-qubit count by $1/6$ and halves the number of stabilizer measurements, yet its minimum distance grows quadratically compared to the standard design and its biased noise threshold is unchanged. The second, called the reduced code, achieves the same hardware savings but trades away single-shot protection for purely $X$ or purely $Z$ noise; instead it remains single-shot under balanced, or depolarizing, noise. In settings where strongly biased noise is likely, either trimmed code offers a less resource-intensive alternative to the full construction. As a concrete illustration, we lift the two-dimensional XZZX surface code to a three-dimensional cubic lattice and show that this ``3D XZZX'' code is an explicit member of the simplified family. Taken together, these bias-tailored single-shot codes provide an adjustable set of code design alternatives, allowing tradeoffs between hardware overhead and noise types.
format Preprint
id arxiv_https___arxiv_org_abs_2507_02239
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Bias-tailored single-shot quantum LDPC codes
Wu, Shixin
Brun, Todd A.
Lidar, Daniel A.
Quantum Physics
Quantum hardware rarely suffers equal amounts of bit-flip ($X$) and phase-flip ($Z$) errors; one type is often much more common than the other. A code that is ``bias-tailored'' can exploit this imbalance, lowering the fault-tolerance overhead. A complementary idea, called "single-shot" error correction, aims to recover from data errors and noisy measurements in a single round of stabilizer readout, avoiding slow repetition cycles. In this work, we combine these two ideas and build a hierarchy of new quantum codes. The full construction starts from the syndrome-encoded hypergraph product code and then tailors it to the dominant error type. The resulting code keeps the single-shot guarantee for every noise model while boosting the threshold whenever $X$ and $Z$ errors are asymmetric. By removing carefully chosen blocks of stabilizers we obtain two trimmed variants. The first, called the simplified code, cuts the physical-qubit count by $1/6$ and halves the number of stabilizer measurements, yet its minimum distance grows quadratically compared to the standard design and its biased noise threshold is unchanged. The second, called the reduced code, achieves the same hardware savings but trades away single-shot protection for purely $X$ or purely $Z$ noise; instead it remains single-shot under balanced, or depolarizing, noise. In settings where strongly biased noise is likely, either trimmed code offers a less resource-intensive alternative to the full construction. As a concrete illustration, we lift the two-dimensional XZZX surface code to a three-dimensional cubic lattice and show that this ``3D XZZX'' code is an explicit member of the simplified family. Taken together, these bias-tailored single-shot codes provide an adjustable set of code design alternatives, allowing tradeoffs between hardware overhead and noise types.
title Bias-tailored single-shot quantum LDPC codes
topic Quantum Physics
url https://arxiv.org/abs/2507.02239