标题： 用大自旋格点模型量子模拟连续场理论 显示英文标题

标题： Quantum simulating continuum field theories with large-spin lattice models

摘要： 模拟量子场论（QFT）的实时动力学是量子模拟器最有前景的应用之一。 为了进行量子模拟，通常需要在希尔伯特空间中进行截断，同时对空间进行离散化。 在这里，我们讨论如何通过使用多级或量子位系统显式构建合适的多体晶格哈密顿量来实现标量QFT的这种正则化，并表明通过对外推大自旋模型的结果进行外推，可以实现连续极限中的定量预测。 通过广泛的矩阵乘积态模拟，我们数值地展示了导致可积的sine-Gordon（sG）QFT可观测量定量一致性的外推序列。 我们进一步展示如何制备静态和移动的孤子激发，并在连续极限下分析它们的散射动力学，结果与半经典模型和定量解析预测一致。 最后，我们说明sG模型的一个非可积扰动如何产生类似于规范理论中弦断裂和等离子体振荡的动力学。 我们的方法可以直接应用于最先进的模拟量子模拟器，为定量研究各种标量场理论以及解决非平衡QFT中的长期问题（如假真空的命运）打开了大门。 显示英文摘要

摘要： Simulating the real-time dynamics of quantum field theories (QFTs) is one of the most promising applications of quantum simulators. Regularizing a bosonic QFT for quantum simulation purposes typically involves a truncation in Hilbert space in addition to a discretization of space. Here, we discuss how to perform such a regularization of scalar QFTs by explicitly constructing suitable many-body lattice Hamiltonians using multi-level or qudit systems, and show that this enables quantitative predictions in the continuum limit by extrapolating results obtained for large-spin models. With extensive matrix-product state simulations, we numerically demonstrate the sequence of extrapolations that leads to quantitative agreement of observables for the integrable sine-Gordon (sG) QFT. We further show how to prepare static and moving soliton excitations, and analyze their scattering dynamics in the continuum limit, in agreement with a semi-classical model and with quantitative analytical predictions. Finally, we illustrate how a non-integrable perturbation of the sG model gives rise to dynamics reminiscent of string breaking and plasma oscillations in gauge theories. Our methods are directly applicable in state-of-the-art analog quantum simulators, opening the door to quantitatively investigating a wide variety of scalar field theories and tackling long-standing questions in non-equilibrium QFT like the fate of the false vacuum.