高分辨率动力学本征谱学：基于超导量子处理器的变分 Trotter 压缩
High-Resolution Dynamical Eigenspectroscopy via Variational Trotter Compression on a Superconducting Qubit Processor
- Zhejiang Province Key Laboratory of Quantum Technology and Device, School of Physics, Zhejiang University（浙江大学物理学院）
- Tencent Quantum Laboratory, Tencent（腾讯量子实验室）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本文提出并实验验证了一种基于变分 Trotter 压缩的动力学本征谱学协议，在 9 量子比特超导处理器上成功提取了 H2 分子和 Fermi-Hubbard 模型的精细能级，精度达 2×10^-3。
中文摘要 AI 辅助
在含噪声中等规模量子设备上追求高分辨率本征谱学常常受到电路深度与相干时间之间权衡的阻碍。在本工作中，我们提出并实验演示了一种动力学本征谱学协议，该协议从时间相关的存活振幅中提取精细的能级结构。为了克服当前超导处理器有限的相干时间窗口，我们采用变分 Trotter 压缩（VTC）作为实用手段来延长高保真幺正演化的持续时间。利用一个多连接的 9 量子比特超导处理器，我们通过量子态层析成像重建了不同键长下 H2 分子以及不同关联区域下 Fermi-Hubbard 模型的时间域自相关信号。通过多频率拟合和傅里叶分析，提取的本征能量与精确对角化值的偏差在 2×10^-3 以内，包括强相互作用区域中的近简并能级。我们的结果确立了实验动力学谱学作为模拟量子化学和强关联晶格系统的稳健且可推广的框架，在近期量子硬件上架起了弱耦合与强耦合区域之间的桥梁。
英文摘要
The pursuit of high-resolution eigenspectroscopy on noisy intermediate-scale quantum devices is often hindered by the trade-off between circuit depth and coherence time. In this work, we introduce and experimentally demonstrate a dynamical eigenspectroscopy protocol that extracts fine-grained energy structures from time-dependent survival amplitudes. To overcome the finite coherence window of current superconducting processors, we employ Variational Trotter Compression (VTC) as a practical means to extend the duration of high-fidelity unitary evolution. Using a multi-connected 9-qubit superconducting processor, we reconstruct the time-domain autocorrelation signal via quantum state tomography for the H2 molecule at different bond lengths and for the Fermi-Hubbard model across different correlation regimes. Through multi-frequency fitting and Fourier analysis, the extracted eigenenergies agree with the exact-diagonalization values to within 2x10^-3, including the near-degenerate levels in the strongly interacting regime. Our results establish experimental dynamical spectroscopy as a robust and generalizable framework for simulating both quantum chemistry and strongly correlated lattice systems, bridging weak- and strong-coupling regimes on near-term quantum hardware.
