Quantum scars and bulk coherence in a symmetry-protected topological phase
Quantum scars and bulk coherence in a symmetry-protected topological phase
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对称保护拓扑相中的量子疤痕和体相干性
DOI：
10.1103/physrevb.104.014424
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发表时间：
2021
影响因子：
3.7
通讯作者：
Jeyaretnam J
中科院分区：
文献类型：
--
作者：
Jeyaretnam J
多体系统中量子疤痕的形成为增强弱纠缠态的相干性提供了一种新的机制。与此同时，边缘模式的相干性，在某些受保护的拓扑（SPT）阶段可以持续远离基态。在这项工作中，我们显示了存在的多体疤痕和它们的影响，在这样的SPT阶段的批量一致性。为此，我们研究的本征态的性质和动力学的相互作用的自旋链与三个网站的“集群”的条款托管aSPT阶段。在弱相互作用下，我们发现在整个光谱范围内，具有体积律纠缠的本征态与具有面积律纠缠的本征态共存。我们表明，后者的一个子集可以构建凭借重复的集群激发的偶数或奇数的子晶格的链，在等距的“塔”的状态，类似于量子多体疤痕的现象。我们进一步证明，这些伤痕累累的本征态支持非热的期望值的本地集群运营商在散装和表现出签名的拓扑顺序，即使在有限的能量密度。从非相互作用的“集群基础”的研究动态的平衡态，我们揭示了nonthermalizing散装动态可以观察到在很长的时间尺度上，如果集群的奇数和偶数网站的大力失谐。在这种情况下，团簇激发基本上仍然局限于两个子晶格之一，使得不均匀的团簇配置不能平衡，整个系统的热化受到阻碍。我们的工作揭示了量子多体疤痕在有限温度下保持SPT顺序的作用，以及在SPT顺序的模型中存在长寿命边缘模式之外的相干体动力学的可能性。
Formation of quantum scars in many-body systems provides a novel mechanism for enhancing coherence of weakly entangled states. At the same time, coherence of edge modes in certain symmetry-protected topological (SPT) phases can persist away from the ground state. In this work we show the existence of many-body scars and their implications on bulk coherence in such an SPT phase. To this end, we study the eigenstate properties and the dynamics of an interacting spin-chain with three-site “cluster” terms hosting aSPT phase. Focusing on the weakly interacting regime, we find that eigenstates with volume-law entanglement coexist with area-law entangled eigenstates throughout the spectrum. We show that a subset of the latter can be constructed by virtue of repeated cluster excitations on the even or odd sublattice of the chain, resulting in an equidistant “tower” of states, analogous to the phenomenology of quantum many-body scars. We further demonstrate that these scarred eigenstates support nonthermal expectation values of local cluster operators in the bulk and exhibit signatures of topological order even at finite energy densities. Studying the dynamics for out-of-equilibrium states drawn from the noninteracting “cluster basis,” we unveil that nonthermalizing bulk dynamics can be observed on long timescales if clusters on odd and even sites are energetically detuned. In this case, cluster excitations remain essentially confined to one of the two sublattices such that inhomogeneous cluster configurations cannot equilibrate and thermalization of the full system is impeded. Our work sheds light on the role of quantum many-body scars in preserving SPT order at finite temperature and the possibility of coherent bulk dynamics in models with SPT order beyond the existence of long-lived edge modes.
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随机矩阵理论和量子自旋链中的纠缠
影响因子：
2.4
作者：
J. Keating;F. Mezzadri
通讯作者：
F. Mezzadri
影响因子：
64.8
作者：
Bernien, Hannes;Schwartz, Sylvain;Lukin, Mikhail D.
通讯作者：
Lukin, Mikhail D.
DOI：
--
发表时间：
2011
期刊：
影响因子：
--
作者：
W. Son;L. Amico;R. Fazio;A. Hamma;S. Pascazio;V. Vedral
通讯作者：
V. Vedral
影响因子：
19.6
作者：
Lavasani, Ali;Alavirad, Yahya;Barkeshli, Maissam
通讯作者：
Barkeshli, Maissam
DOI：
10.1088/1742-5468/aa73f0
发表时间：
2017-06-01
影响因子：
2.4
作者：
Kemp, Jack;Yao, Norman Y.;Fendley, Paul
通讯作者：
Fendley, Paul