Real-time Dynamics in U(1) Lattice Gauge Theories with Tensor Networks
Real-time Dynamics in U(1) Lattice Gauge Theories with Tensor Networks
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DOI：
10.1103/physrevx.6.011023
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发表时间：
2015-05
期刊：
影响因子：
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通讯作者：
T. Pichler;M. Dalmonte;E. Rico;P. Zoller;S. Montangero
中科院分区：
文献类型：
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作者：
T. Pichler;M. Dalmonte;E. Rico;P. Zoller;S. Montangero
张量网络算法为处理晶格规范理论中的实时依赖问题提供了一条合适的途径，使非平衡动力学的研究成为可能。我们分析了一个（1+1）维的U(1)晶格规范理论，该理论类似于一维的量子电动力学，它显示了弦断裂：在淬灭实验中，电荷之间的约束弦可以自发断裂，根据Schwinger机制产生电荷-反电荷对。我们通过电场和粒子波动研究了激励在系统中的实时传播；我们确定了弦断裂的动态状态图，并定量地评估了大规模生产的时间尺度。我们还表明，量子相关的时间演化可以通过二部冯·诺伊曼熵来检测，从而表明施温格机制与纠缠扩散紧密相关。为了展示该模拟平台的各种可能应用，我们展示了如何跟踪介子之间的实时散射过程以及散射过程中纠缠的产生。最后，我们测试了这些动力学的量子模拟的质量，量化了冷原子、捕获离子和超导电路系统中可能存在的缺陷的作用。我们的研究结果表明，纠缠特性可以用来加深我们对规范理论实时动力学中的基本现象的理解，如弦断裂和碰撞。
Tensor network algorithms provide a suitable route for tackling real-time dependent problems in lattice gauge theories, enabling the investigation of out-of-equilibrium dynamics. We analyze a U(1) lattice gauge theory in (1+1) dimensions in the presence of dynamical matter for different mass and electric field couplings, a theory akin to quantum-electrodynamics in one-dimension, which displays string-breaking: the confining string between charges can spontaneously break during quench experiments, giving rise to charge-anticharge pairs according to the Schwinger mechanism. We study the real-time spreading of excitations in the system by means of electric field and particle fluctuations: we determine a dynamical state diagram for string breaking and quantitatively evaluate the time-scales for mass production. We also show that the time evolution of the quantum correlations can be detected via bipartite von Neumann entropies, thus demonstrating that the Schwinger mechanism is tightly linked to entanglement spreading. To present the variety of possible applications of this simulation platform, we show how one could follow the real-time scattering processes between mesons and the creation of entanglement during scattering processes. Finally, we test the quality of quantum simulations of these dynamics, quantifying the role of possible imperfections in cold atoms, trapped ions, and superconducting circuit systems. Our results demonstrate how entanglement properties can be used to deepen our understanding of basic phenomena in the real-time dynamics of gauge theories such as string breaking and collisions.