We discuss a method based on sampling minimally entangled typical thermal states (METTS) that can simulate finite temperature quantum systems with a computational cost comparable to ground state DMRG. Detailed implementations of each step of the method are presented, along with efficient algorithms for working with matrix product states and matrix product operators. We furthermore explore how properties of METTS can reveal characteristic order and excitations of systems and discuss why METTS form an efficient basis for sampling. Finally, we explore the extent to which the average entanglement of a METTS ensemble is minimal.
Topological Minimally Entangled States via Geometric Measure
在这里，我们展示了如何最小纠缠态（MES）的二维系统的拓扑顺序可以识别使用的纠缠的几何措施。我们表明这一点，通过最大限度地减少这一措施的双重半，双斐波那契和环面代码模型上的环面与非平凡的拓扑分区。我们的计算要么是对小系统尺寸的准精确计算，要么是使用[R]中的张量网络方法。Orus，T. C. Wei，O. Buerschaper，A. Garcia-Saez，arXiv：1406.0585]用于大尺寸。作为我们方法的副产品，我们看到几何纠缠的最小化也可以确定给定模型中阿贝尔准粒子激发的数量。本文的结果为从二维量子晶格模型的基态多体纠缠结构中提取其完整的拓扑信息提供了一种非常有效和精确的方法。
Spectroscopy and complex-time correlations using minimally entangled typical thermal states
Arnold Sommerfeld Center for Theoretical Physics, University of Munich（慕尼黑大学阿诺德·索末菲理论物理中心）；Max Planck Institute for the Physics of Complex Systems（马克斯·普朗克复杂系统物理研究所）；Lanzhou Center for Theoretical Physics, Key Laboratory of Quantum Theory and Applications of MoE, Key Laboratory of Theoretical Physics of Gansu Province, and School of Physical Science and Technology, Lanzhou University（兰州大学物理科学与技术学院量子理论与应用教育部重点实验室甘肃省理论物理重点实验室兰州理论物理中心）；Laboratoire Léon Brillouin, CEA, CNRS, Université Paris-Saclay（巴黎萨克雷大学CEA-CNRS勒翁·布里渊实验室）；Laboratoire de Physique Théorique et Modélisation, CNRS UMR 8089, CY Cergy Paris Université（CY塞吉-巴黎大学CNRS UMR 8089理论物理与建模实验室）
Minimally Entangled Typical Thermal States for Classical and Quantum Simulation of 1+1-Dimensional $\mathbb Z_2$ Lattice Gauge Theory at Finite Temperature and Density
