Self-verifying variational quantum simulation of lattice models
Self-verifying variational quantum simulation of lattice models
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DOI：
10.1038/s41586-019-1177-4
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发表时间：
2019-05-16
期刊：
影响因子：
64.8
通讯作者：
Zoller, P.
中科院分区：
文献类型：
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作者：
Kokail, C.;Maier, C.;Zoller, P.
混合经典量子算法旨在使用经典计算机和量子协处理器之间的反馈回路以变体方式解决优化问题，同时受益于量子资源。在这里，我们提出的实验证明了凝聚态和高能物理中晶格模型的自我验证、混合、变分量子模拟。与模拟量子模拟相比，这种方法放弃了直接在实验室中实现目标哈密顿量的要求，从而能够研究各种以前难以处理的目标模型。我们重点关注晶格施温格模型，一种一维量子电动力学规范理论。我们的量子协处理器是一个可编程的捕获离子模拟量子模拟器，具有多达 20 个量子位，能够生成符合目标哈密顿量对称性的纠缠试验状态族。我们确定基态、能隙，此外，通过测量施温格哈密顿量的方差，我们提供能量的算法误差，从而向验证量子模拟迈出了一步。
Hybrid classical-quantum algorithms aim to variationally solve optimization problems using a feedback loop between a classical computer and a quantum co-processor, while benefiting from quantum resources. Here we present experiments that demonstrate self-verifying, hybrid, variational quantum simulation of lattice models in condensed matter and high-energy physics. In contrast to analogue quantum simulation, this approach forgoes the requirement of realizing the targeted Hamiltonian directly in the laboratory, thus enabling the study of a wide variety of previously intractable target models. We focus on the lattice Schwinger model, a gauge theory of one-dimensional quantum electrodynamics. Our quantum co-processor is a programmable, trapped-ion analogue quantum simulator with up to 20 qubits, capable of generating families of entangled trial states respecting the symmetries of the target Hamiltonian. We determine ground states, energy gaps and additionally, by measuring variances of the Schwinger Hamiltonian, we provide algorithmic errors for the energies, thus taking a step towards verifying quantum simulation.