标题： 使用全局控制在量子模拟器中估计基态性质 显示英文标题

标题： Estimating ground-state properties in quantum simulators with global control

摘要： 准确确定量子多体系统的基态性质仍然是量子模拟的主要挑战之一。 在本工作中，我们提出了一种协议，仅使用目标哈密顿量下的全局时间演化来估计基态能量。 这避免了传统量子相位估计算法中通常需要的受控操作，并将算法的适用性扩展到模拟模拟器。 我们的方法从初始基态近似下的Loschmidt回波测量中提取能量差异，将其与直接能量测量相结合，并求解一组方程以推断各个本征能量。 我们在自由费米子系统上对这一协议进行了基准测试，显示出相对于初始状态的直接能量测量有数量级的精度提升，且准确性随着初始状态保真度的提高而迅速改善，并在数百个模式中持续存在。 我们进一步证明了该方法适用于二维伊辛模型和费米-赫巴德模型，并表明该方法自然地扩展到其他可观测量，如序参数。 最后，我们分析了实验缺陷的影响并提出了误差缓解策略。 这些结果确立了一种使用全局控制量子模拟器高精度计算物理相关量的实用途径。 显示英文摘要

摘要： Accurately determining ground-state properties of quantum many-body systems remains one of the major challenges of quantum simulation. In this work, we present a protocol for estimating the ground-state energy using only global time evolution under a target Hamiltonian. This avoids the need for controlled operations that are typically required in conventional quantum phase estimation and extends the algorithm applicability to analog simulators. Our method extracts energy differences from measurements of the Loschmidt echo over an initial ground-state approximation, combines them with direct energy measurements, and solves a set of equations to infer the individual eigenenergies. We benchmark this protocol on free-fermion systems, showing orders-of-magnitude precision gains over direct energy measurements on the initial state, with accuracy improving rapidly with initial-state fidelity and persisting for hundreds of modes. We further demonstrate applicability to the 2D Ising and Fermi-Hubbard models and show that the approach extends naturally to other observables such as order parameters. Finally, we analyze the effect of experimental imperfections and propose error-mitigation strategies. These results establish a practical route to compute physically relevant quantities with high precision using globally controlled quantum simulators.