发表机构
SKKU Advanced Institute of Nano Technology (SAINT), Sungkyunkwan University; Yonsei University（成均馆大学 SKKU 纳米技术高级研究所; 延世大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出用于分子量子动力学模拟的近最优量子原语，利用广义雅可比-安格尔展开合成非线性多模玻色子相位门，使基准电路缩短约三分之一，并在二氧化碳模型上验证了可行性。
AI 中文摘要
同时量子力学处理电子和原子核的分子量子动力学模拟对于预测化学反应至关重要。在经典计算中，对这两类粒子进行全波函数表示所需的资源随其数量呈指数增长。振荡器-量子比特处理器（包括离子阱和电路量子电动力学设备）用量子比特表示电子态，用振荡器表示核振动。它们的原生操作产生线性振动耦合相互作用，从中可以构建可编程的非谐相互作用。乘积公式方法通过重复小的非对易相位步骤来构建相应的相位门，而量子信号处理（QSP）方法则用傅里叶级数直接近似每个门。模拟中会依次应用许多这样的门，因此累积的成本和误差限制了动力学可被跟踪的时间长度。我们提出了用于分子量子动力学模拟的近最优量子原语，涵盖两类粒子的表示及其相互作用。我们利用QSP中的广义雅可比-安格尔（GJA）展开来合成非线性和多模玻色子相位门，其成本在相互作用强度和精度两方面都近最优地增长。我们的相互作用模型和门合成各自具有独立的精度设置。将这些设置结合起来，使我们的多模基准电路比之前的直接QSP方法短约三分之一。然后，我们模拟了简化二氧化碳模型中伸缩振动和弯曲振动之间的能量交换。在电路量子电动力学噪声下，短时模拟在量子比特和振荡器寿命接近2毫秒和5毫秒时勉强未达到我们的精度标准。这些寿命标志着在近期振荡器-量子比特处理器上模拟非谐多模分子量子动力学道路上的一个具体里程碑。
英文摘要
Molecular quantum dynamics simulations that treat both electrons and nuclei quantum mechanically are crucial for predicting chemical reactions. With classical computation, a full wave-function representation of both types of particles requires resources that grow exponentially with their number. Oscillator-qubit processors, including trapped-ion and circuit QED devices, represent electronic states with qubits and nuclear vibrations with oscillators. Their native operations produce linear vibronic interactions, from which programmable anharmonic interactions can be built. Product-formula approaches build the corresponding phase gates by repeating small noncommuting phase steps, and quantum signal processing (QSP) approaches approximate each gate directly with a Fourier series. Simulations apply many such gates in sequence, so accumulated cost and error limit how long the dynamics can be followed. We propose near-optimal quantum primitives for molecular quantum dynamics simulation, covering the representations of both types of particles and their interactions. We synthesize nonlinear and multimode bosonic phase gates using generalized Jacobi-Anger (GJA) expansions within QSP, with a cost that grows near-optimally in both interaction strength and precision. Our interaction model and gate synthesis each have their own accuracy setting. Chosen together, these settings make our multimode benchmark circuits about one-third shorter than those of the previous direct QSP approach. We then simulate energy exchange between the stretching and bending vibrations of a simplified carbon dioxide model. With circuit-QED noise, a short simulation narrowly misses our accuracy criteria at qubit and oscillator lifetimes near 2 ms and 5 ms. These lifetimes mark a concrete checkpoint on the way to simulating anharmonic multimode molecular quantum dynamics on near-term oscillator-qubit processors.
Comments30 pages, 6 figures, 2 tables
