论文标题
自适应变分量子动力学模拟
Adaptive Variational Quantum Dynamics Simulations
论文作者
论文摘要
我们提出了一种通用的自适应方法，用于构建基于麦克拉克兰（McLachlan）的变分原理的高度准确量子动力学模拟，以构建变异波函数。关键思想是沿时间进化路径动态扩展变异性ANSATZ，以使``McLachlan距离''（是模拟精度的度量）保持在设定阈值以下。我们将这种自适应变分量子动力学模拟（AVQD）方法应用于可集成的Lieb-Schultz-Mattis自旋链和不可整合的混合场ISING模型，在该模型中，它可以捕获有限速率和较高的储蓄后量化动力学。准备时间进化状态的AVQDS量子电路比从一阶小动物中获得的量子较浅，并且最多包含两个数量级的CNOT GATE操作。我们设想，将通过AVQDS框架使量子多体系统对量子多体系统进行广泛的动态模拟。
We propose a general-purpose, self-adaptive approach to construct variational wavefunction ansätze for highly accurate quantum dynamics simulations based on McLachlan's variational principle. The key idea is to dynamically expand the variational ansatz along the time-evolution path such that the ``McLachlan distance'', which is a measure of the simulation accuracy, remains below a set threshold. We apply this adaptive variational quantum dynamics simulation (AVQDS) approach to the integrable Lieb-Schultz-Mattis spin chain and the nonintegrable mixed-field Ising model, where it captures both finite-rate and sudden post-quench dynamics with high fidelity. The AVQDS quantum circuits that prepare the time-evolved state are much shallower than those obtained from first-order Trotterization and contain up to two orders of magnitude fewer CNOT gate operations. We envision that a wide range of dynamical simulations of quantum many-body systems on near-term quantum computing devices will be made possible through the AVQDS framework.
