论文标题
克服量子多体动力学中的纠缠屏障，通过时空双重性
Overcoming the entanglement barrier in quantum many-body dynamics via space-time duality
论文作者
论文摘要
描述量子多体系统的非平衡性能由于波函数中的纠缠高而具有挑战性。我们通过影响矩阵（IM）描述了局部可观察物的演变，该矩阵编码多体系统作为局部子系统的环境的影响。最近的著作发现，在许多动态状态下，无限系统的IM具有较低的时间纠缠，并且可以有效地表示为基质产物状态（MPS）。然而，IM遇到高度纠缠中间状态的直接迭代构造 - 时间纠缠屏障（TEB）。我们认为TEB无处不在，并通过半经典的准粒子图片阐明了其物理起源，该图片准确地捕获了可集成的旋转链的行为。此外，我们表明在混乱的自旋链中也出现了TEB，这些链条缺乏明确的准粒子。基于这些见解，我们制定了一种替代的轻锥生长算法，该算法可避免使用TEB，从而为MPS提供了有效的热力学限制IM。这项工作揭示了IM方法用于热化和运输的效率的起源。
Describing non-equilibrium properties of quantum many-body systems is challenging due to high entanglement in the wavefunction. We describe evolution of local observables via the influence matrix (IM), which encodes the effects of a many-body system as an environment for local subsystems. Recent works found that in many dynamical regimes the IM of an infinite system has low temporal entanglement and can be efficiently represented as a matrix-product state (MPS). Yet, direct iterative constructions of the IM encounter highly entangled intermediate states - a temporal entanglement barrier (TEB). We argue that TEB is ubiquitous, and elucidate its physical origin via a semiclassical quasiparticle picture that exactly captures the behavior of integrable spin chains. Further, we show that a TEB also arises in chaotic spin chains, which lack well-defined quasiparticles. Based on these insights, we formulate an alternative light-cone growth algorithm, which provably avoids TEB, thus providing an efficient construction of the thermodynamic-limit IM as a MPS. This work uncovers the origin of the efficiency of the IM approach for thermalization and transport.
