Simulating chemical systems is highly sought after and computationally challenging, as the simulation cost exponentially increases with the system size. Quantum computers have been proposed as a computational means to overcome this bottleneck. Most efforts recently have been spent on determining the ground states of chemical systems. Hardness results and the lack of efficient heuristics for initial-state generation sheds doubt on the feasibility. Here we propose an inherently efficient approach for solving chemical simulation problems, meaning it requires quantum circuits of size scaling polynomially in relevant system parameters. If a set of assumptions can be satisfied, our approach finds good initial states by assembling initial states for dynamical simulation in a scattering tree. We discuss a variety of quantities of chemical interest that can be measured based on quantum simulation, e.g. of a reaction, succeeding the initial state preparation.

翻译：化学系统的模拟是备受追求且计算上极具挑战的任务，因为模拟成本随系统规模呈指数增长。量子计算机被提议作为克服这一瓶颈的计算手段。近期大多数研究集中于确定化学系统的基态。但复杂度结果以及缺乏有效的初始态生成启发式方法，使其实施可行性存疑。本文提出一种天然高效的化学模拟问题求解方法，这意味着该方法所需量子电路的规模与相关系统参数呈多项式关系。若一组假设条件能够满足，我们的方法通过散射树中动力学模拟的初始态组装来寻找良好初始态。我们讨论了在初始态制备后，基于量子模拟可测量的多种化学相关量（例如化学反应过程中的量）。