用傅里叶神经算子高效模拟量子自旋系统演化,实现超长时预测。
Fourier Neural Operators for Learning Dynamics in Quantum Spin Systems
- 基于傅里叶神经算子建模量子态时间演化,突破传统网络泛化瓶颈。
- 20比特系统下预测时长翻倍,相对误差仅5.8%,推理速度提升万倍。
- 通过哈密顿量可观测量降维,适合高维量子系统快速仿真。
傅里叶神经算子(FNOs)在处理函数型数据方面表现优异,适用于由偏微分方程生成的任务。这使其成为模拟量子波函数时间演化的一种有效方法,该任务虽计算复杂但对研究量子系统至关重要。本文利用FNOs建模量子自旋系统的演化,因其代表性量子动力学特性被选中。我们比较了两种不同FNO架构,在随机与低能输入态上评估其学习与预测能力。发现固定维度的普通神经网络(如U-Net)在训练时间区间外泛化能力有限,而FNO能可靠捕获底层时间演化算符,实现对未见时间的有效外推。此外,我们将方法聚焦于约多项式规模(∼poly(n))的哈密顿量可观测量,而非完整的2^n维量子态,大幅降低模型输入、输出及维度。此方法证明了FNO能有效从高维空间提取信息至低维空间。在20量子比特系统上进行数值实验,将可观测量外推至两倍训练时间,相对误差为5.8%。相较于数值时间演化方法,FNO在20量子比特系统上实现约10⁴倍的推理加速。对训练时间之外的可观测量外推具有重要意义,可显著扩展当前量子硬件相干时间与可处理张量网络电路深度限制下的可模拟系统范围。
原文摘要 · Abstract (English)
Fourier Neural Operators (FNOs) excel on tasks using functional data, such as those originating from partial differential equations. Such characteristics render them an effective approach for simulating the time evolution of quantum wavefunctions, which is a computationally challenging, yet coveted task for studying quantum systems. In this manuscript, we use FNOs to model the evolution of quantum spin systems, so chosen due to their representative quantum dynamics. We explore two distinct FNO architectures, examining their performance for learning and predicting time evolution on both random and low-energy input states. We find that standard neural networks in fixed dimensions, such as U-Net, exhibit limited ability to extrapolate beyond the training time interval, whereas FNOs reliably capture the underlying time-evolution operator, generalizing effectively to unseen times. Additionally, we apply FNOs to a compact set of Hamiltonian observables ($\sim\text{poly}(n)$) instead of the entire $2^n$ quantum wavefunction, which greatly reduces the size of our FNO inputs, outputs and model dimensions. Moreover, this Hamiltonian observable-based method demonstrates that FNOs can effectively distill information from high-dimensional spaces into lower-dimensional spaces. Using this approach, we perform numerical experiments on a 20-qubit system and extrapolate Hamiltonian observables to twice the training time with a relative error of $5.8\%$. Relative to numerical time-evolution methods, FNO achieves an inference speedup of approximately $10^{4}\times$ for 20-qubit systems. The extrapolation of Hamiltonian observables to times later than those used in training is of particular interest, as this stands to fundamentally increase the simulatability of quantum systems past both the coherence times of contemporary quantum architectures and the circuit-depths of tractable tensor networks.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。