标题： 同时VQE用于模拟施温格模型的激发态 显示英文标题

标题： Concurrent VQE for Simulating Excited States of the Schwinger Model

摘要： 这项工作探讨了同时变分量子本征求解器（cVQE）在计算施温格模型激发态中的应用。 通过设计合适的ansatz电路，利用通用的SO(4)或SO(8)量子比特门，我们展示了如何在背景电场为零和非零的情况下，使用一个、两个和三个辅助量子比特高效地获得最低的两个、四个和八个本征态。 通过经典模拟生成的量子电路，使用张量网络技术，我们证明了我们的方法能够计算最多$\mathcal{O}(100)$个量子比特系统的最低两个本征态。 鉴于我们的方法允许精确测量低能谱，我们还提出了一种新的技术来估计基于能量间隙的格点加性质量重整化。 作为原理验证计算，我们在量子硬件上用一个辅助量子比特和四个物理量子比特制备了基态和第一激发态，证明了使用cVQE模拟激发态的实用性。 显示英文摘要

摘要： This work explores the application of the concurrent variational quantum eigensolver (cVQE) for computing excited states of the Schwinger model. By designing suitable ansatz circuits utilizing universal SO(4) or SO(8) qubit gates, we demonstrate how to efficiently obtain the lowest two, four, and eight eigenstates with one, two, and three ancillary qubits for both vanishing and non-vanishing background electric field cases. Simulating the resulting quantum circuits classically with tensor network techniques, we demonstrate the capability of our approach to compute the two lowest eigenstates of systems with up to $\mathcal{O}(100)$ qubits. Given that our method allows for measuring the low-lying spectrum precisely, we also present a novel technique for estimating the additive mass renormalization of the lattice based on the energy gap. As a proof-of-principle calculation, we prepare the ground and first-excited states with one ancillary and four physical qubits on quantum hardware, demonstrating the practicality of using the cVQE to simulate excited states.