Channel and carrier adapted quantum error correction

基于通用综合征的噪声自适应量子纠错恢复

Universal syndrome-based recovery for noise-adapted quantum error correction

本文提出一种算法方法识别任意码和噪声过程的错误综合征，并开发基于综合征的Petz恢复映射，在IBM量子硬件上实现噪声自适应QEC协议的盈亏平衡，量子比特T1时间提升三倍。

Channel-Adapted Quantum Error Correction

Quantum error correction (QEC) is an essential concept for any quantum information processing device. Typically, QEC is designed with minimal assumptions about the noise process; this generic assumption exacts a high cost in efficiency and performance. In physical systems, errors are not likely to be arbitrary; rather we will have reasonable models for the structure of quantum decoherence. We may choose quantum error correcting codes and recovery operations that specifically target the most likely errors. We present a convex optimization method to determine the optimal (in terms of average ent…

演示具有适应噪声的量子错误校正的破平衡性能

Demonstrating Noise-adapted Quantum Error Correction With Break-Even Performance

本研究利用适应噪声的3量子位量子错误校正方案，在IBM量子硬件上展示针对本征振幅阻尼噪声的破平衡性能，通过变分量子电路实现高效编码和解码，并结合动态解耦技术提高量子比特稳定性。

非马尔可夫噪声的自适应量子纠错

Noise-adapted Quantum Error Correction for Non-Markovian Noise

针对非马尔可夫噪声，利用Petz恢复映射推广近似QEC条件，证明其即使在最大噪声下也能保护码空间，且优于标准稳定子码，并构造性能相近的马尔可夫Petz映射。

Wigner distribution on a double cylinder phase space for studying quantum error correction protocol

We introduce a quasi-probability phase space distribution with two pairs of azimuthal-angular coordinates. This representation is well adapted to describe quantum systems with discrete symmetry. Quantum error correction of states encoded in continuous variables using translationally invariant states is studied as an example of application. We also propose an experimental scheme for measuring such new distribution.

利用砖块Clifford电路进行误差校正

Error correction with brickwork Clifford circuits

本文研究了随机一维Clifford砖块电路在对数深度下的量子误差校正能力，并给出了误差校正所需的深度上下界。

开放量子系统基于测量适应的时间粗粒化模型降阶

Model Order Reduction for Open Quantum Systems Based on Measurement-adapted Time-coarse Graining

本文提出基于测量适应粗粒化的模型降阶技术，通过时间尺度τ和频带中心ω_0优化低阶模型，推导出有效量子主方程并提升解释能力。

针对振幅阻尼噪声的噪声自适应qudit码

Noise-adapted qudit codes for amplitude-damping noise

本文提出一种针对振幅阻尼噪声的$[4,1]$ qudit纠错码，通过综合征提取实现噪声自适应恢复，保真度损失为$\mathcal{O}(γ^{2})$，并推广至$[2M+2, M]$码族。

Quantum Error Correction with Quantum Autoencoders

Active quantum error correction is a central ingredient to achieve robust quantum processors. In this paper we investigate the potential of quantum machine learning for quantum error correction in a quantum memory. Specifically, we demonstrate how quantum neural networks, in the form of quantum autoencoders, can be trained to learn optimal strategies for active detection and correction of errors, including spatially correlated computational errors as well as qubit losses. We highlight that the denoising capabilities of quantum autoencoders are not limited to the protection of specific states b…

Deterministic correction of qubit loss

The loss of qubits - the elementary carriers of quantum information - poses one of the fundamental obstacles towards large-scale and fault-tolerant quantum information processors. In this work, we experimentally demonstrate a complete toolbox and the implementation of a full cycle of qubit loss detection and correction on a minimal instance of a topological surface code. This includes a quantum non-demolition measurement of a qubit loss event that conditionally triggers a restoration procedure, mapping the logical qubit onto a new encoding on the remaining qubits. The demonstrated methods, imp…

Qudit与Qubit对比：高维纠错码的模拟性能

Qudit vs. Qubit: Simulated performance of error correction codes in higher dimensions

本研究对比qudit与qubit的纠错性能，通过构建带多维噪声模型和适配解码器的最小qudit纠错码线路并模拟，引入flag qudit抗钩错误后，2、3、5维qudit均获约10^-4量级的可比错误阈值，验证了高维qudit纠错的可行性与低开销潜力。

如何超越高斯量子纠错与纠缠高斯态蒸馏中的不可行极限？

How to surpass no-go limits in Gaussian quantum error correction and entangled Gaussian state distillation?

本文提出仅依赖局域高斯资源的高斯量子纠错协议，利用纠缠高斯态门隐形传态实现部分转置，从两个含噪高斯信道构造双模噪声极化信道，并扩展为非局域高斯态蒸馏协议，从而超越高斯量子信息处理中的不可行极限。

trapped 离子量子计算机中链损失的校正

Correction of chain losses in trapped ion quantum computers

本研究提出了一种基于量子错误校正码、信标量子比特和适应性解码器的方案，用于校正受困离子量子计算机中长链的量子比特丢失问题。

无测量量子纠错的优化方案：针对偏置噪声

Measurement-free quantum error correction optimized for biased noise

本文提出无测量量子纠错方案，针对中性原子平台的偏置噪声优化，通过减少噪声模型至泡利Z误差，提升误差率阈值，为构建可扩展的量子纠错系统奠定基础。

Approximate quantum error correction for generalized amplitude damping errors

We present analytic estimates of the performances of various approximate quantum error correction schemes for the generalized amplitude damping (GAD) qubit channel. Specifically, we consider both stabilizer and nonadditive quantum codes. The performance of such error-correcting schemes is quantified by means of the entanglement fidelity as a function of the damping probability and the non-zero environmental temperature. The recovery scheme employed throughout our work applies, in principle, to arbitrary quantum codes and is the analogue of the perfect Knill-Laflamme recovery scheme adapted to …

量子分组Turbo码

Quantum Block Turbo Codes

本文提出作为Turbo乘积码量子类似物的量子分组Turbo码理论，描述其迭代译码算法并在去极化信道上针对不同分量码模拟性能，推动量子纠错理论发展。

Quantum fluctuations of Coulomb Potential as a Source of Flicker Noise. The Influence of Heat Bath

The power spectrum of finite-temperature quantum electromagnetic fluctuations produced by elementary charge carriers under the influence of external electric field is investigated. It is found that under the combined action of the photon heat bath and the external field, the low-frequency asymptotic of the power spectrum is modified both qualitatively and quantitatively. The new term in the power spectrum is inversely proportional to, but is odd in frequency. It comes from the connected part of the correlation function, and is related to the temperature and external field corrections to the ph…

用于高效光子量子纠错的自旋增强可观测量

Spin-augmented observables for efficient photonic quantum error correction

本研究提出利用微柱腔中固态发射器的自旋态作为测量量子比特，通过圆双折射作用与光子数据量子比特相互作用，实现高效光子量子纠错，该方案可适配多种资源需求且在强耦合区具有高纠缠保真度和腔损耗耐受性。

Dissipation-induced continuous quantum error correction for superconducting circuits

Quantum error correction (QEC) is a crucial step towards long coherence times required for efficient quantum information processing (QIP). One major challenge in this direction concerns the fast real-time analysis of error syndrome measurements and the associated feedback control. Recent proposals on autonomous QEC (AQEC) have opened new perspectives to overcome this difficulty. Here, we design an AQEC scheme based on quantum reservoir engineering adapted to superconducting qubits. We focus on a three-qubit bit-flip code, where three transmon qubits are dispersively coupled to a few low-Q reso…

受机器学习启发的噪声强度自适应近似量子码

Noise-strength-adapted approximate quantum codes inspired by machine learning

本研究借助混合量子-经典机器学习发现两种具备噪声强度自适应特性的新型4量子比特振幅阻尼码，性能优于传统码，并推广至任意规模码族及二项式码变体，证明噪声强度适配可提升纠错能力。

Quantum Error Correction Code in the Hamiltonian Formulation

The Hamiltonian model of quantum error correction code in the literature is often constructed with the help of its stabilizer formalism. But there have been many known examples of nonadditive codes which are beyond the standard quantum error correction theory using the stabilizer formalism. In this paper, we suggest the other type of Hamiltonian formalism for quantum error correction code without involving the stabilizer formalism, and explain it by studying the Shor nine-qubit code and its generalization. In this Hamiltonian formulation, the unitary evolution operator at a specific time is a …

基于密度基组校正的化学精度量子计算捷径

Shortcut to Chemically Accurate Quantum Computing via Density-based Basis-set Correction

本文提出将基于密度的基组校正（DBBSC）与量子计算拟设结合，通过实时定制基组逼近完备基组极限，在有限量子比特资源下实现化学精度量子计算，并可兼作量子硬件的经典后验能量校正。

Preparing Renormalization Group Fixed Points on NISQ Hardware

Noisy intermediate-scale quantum (NISQ) hardware is typically limited to low-depth quantum circuits to limit the number of opportunities for introduction of error by unreliable quantum gates. A less-explored alternative approach is to repeatedly apply a quantum channel with a desired quantum state as a stable fixed point. Increased circuit depth can in this case be beneficial rather than harmful due to dissipative self-correction. The quantum channels constructed from MERA circuits can be interpreted in terms of the renormalization group(RG), and their fixed points are RG fixed points, i.e. sc…

From Quantum Codes to Gravity: A Journey of Gravitizing Quantum Mechanics

In this note, I review a recent approach to quantum gravity that "gravitizes" quantum mechanics by emerging geometry and gravity from complex quantum states. Drawing further insights from tensor network toy models in AdS/CFT, I propose that approximate quantum error correction codes, when re-adapted into the aforementioned framework, also has promise in emerging gravity in near-flat geometries.

非阿贝尔码中的混合态拓扑序与纠错阈值：严格结果

Mixed-state topological order and error-correction thresholds in non-Abelian codes: rigorous results

研究非阿贝尔码受噪声影响时的恢复阈值，提出通用严格技术，可捕捉二维码受任意局部噪声影响，证明一定噪声强度下逻辑信息可高精度恢复，噪声破坏态有混合态拓扑序特征，还介绍了方法在高维及相关噪声模型的应用。

超几何量子纠错码的系统方法

Systematic Approach to Hyperbolic Quantum Error Correction Codes

本文提出基于超几何晶格的量子纠错码系统构建框架，通过超几何晶体学进展，开发了高效识别面循环和非平凡循环的超几何循环基算法，实现了CSS码的规模化评估与模拟，展示了超几何量子纠错码在编码率、误差阈值和码距等性能上的优势。