Biased Gottesman-Kitaev-Preskill repetition code

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Stafford, Matthew P., Menicucci, Nicolas C.
Format: Preprint
Veröffentlicht: 2022
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866929234531844096
author Stafford, Matthew P.
Menicucci, Nicolas C.
author_facet Stafford, Matthew P.
Menicucci, Nicolas C.
contents Continuous-variable quantum computing architectures based upon the Gottesmann-Kitaev-Preskill (GKP) encoding have emerged as a promising candidate because one can achieve fault-tolerance with a probabilistic supply of GKP states and Gaussian operations. Furthermore, by generalising to rectangular-lattice GKP states, a bias can be introduced and exploited through concatenation with qubit codes that show improved performance under biasing. However, these codes (such as the XZZX surface code) still require weight-four stabiliser measurements and have complex decoding requirements to overcome. In this work, we study the code-capacity behaviour of a rectangular-lattice GKP encoding concatenated with a repetition code under an isotropic Gaussian displacement channel. We find a numerical threshold of $σ= 0.599$ for the noise's standard deviation, which outperforms the biased GKP planar surface code with a trade-off of increased biasing at the GKP level. This is all achieved with only weight-two stabiliser operators and simple decoding at the qubit level. Furthermore, with moderate levels of bias (aspect ratio $\leq 2.4$) and nine or fewer data modes, significant reductions in logical error rates can still be achieved for $σ\leq 0.3$, opening the possibility of using GKP-biased repetition codes as a simple low-level qubit encoding for further concatenation.
format Preprint
id arxiv_https___arxiv_org_abs_2212_11397
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Biased Gottesman-Kitaev-Preskill repetition code
Stafford, Matthew P.
Menicucci, Nicolas C.
Quantum Physics
Continuous-variable quantum computing architectures based upon the Gottesmann-Kitaev-Preskill (GKP) encoding have emerged as a promising candidate because one can achieve fault-tolerance with a probabilistic supply of GKP states and Gaussian operations. Furthermore, by generalising to rectangular-lattice GKP states, a bias can be introduced and exploited through concatenation with qubit codes that show improved performance under biasing. However, these codes (such as the XZZX surface code) still require weight-four stabiliser measurements and have complex decoding requirements to overcome. In this work, we study the code-capacity behaviour of a rectangular-lattice GKP encoding concatenated with a repetition code under an isotropic Gaussian displacement channel. We find a numerical threshold of $σ= 0.599$ for the noise's standard deviation, which outperforms the biased GKP planar surface code with a trade-off of increased biasing at the GKP level. This is all achieved with only weight-two stabiliser operators and simple decoding at the qubit level. Furthermore, with moderate levels of bias (aspect ratio $\leq 2.4$) and nine or fewer data modes, significant reductions in logical error rates can still be achieved for $σ\leq 0.3$, opening the possibility of using GKP-biased repetition codes as a simple low-level qubit encoding for further concatenation.
title Biased Gottesman-Kitaev-Preskill repetition code
topic Quantum Physics
url https://arxiv.org/abs/2212.11397