Transport properties across the many-body localization transition in quasiperiodic and random systems
Transport properties across the many-body localization transition in quasiperiodic and random systems
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DOI：
10.1103/physrevb.96.104205
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发表时间：
2017-07
影响因子：
3.7
通讯作者：
F. Setiawan;D. Deng;J. Pixley
中科院分区：
文献类型：
--
作者：
F. Setiawan;D. Deng;J. Pixley
本文从理论上研究了无限温度下一维相互作用准周期系统的输运性质。我们比较和对比的动力学输运性质跨多体局域化（MBL）过渡的准周期和随机模型。使用精确对角化，我们计算的光学电导率$\sigma（\omega）$和返回概率$R（\tau）$和研究他们的平均低频和长时间的幂律行为，分别。我们表明，低能量的输运动力学是显着不同的热和MBL阶段的准周期和随机模型，并发现准周期模型的扩散和MBL制度比随机系统中的更强大。使用的DC电导率的分布，我们量化的样品到样品和状态到状态的波动的$\sigma（\omega）$整个MBL过渡的贡献。我们发现，激活的动力学标度分析在准周期模型中效果不佳，但在随机模型中，估计的激活指数约为0.9$。我们认为，在准周期系统的MBL过渡附近，临界本征态引起有限尺寸系统的次扩散交叉制度。
We theoretically study transport properties in one-dimensional interacting quasiperiodic systems at infinite temperature. We compare and contrast the dynamical transport properties across the many-body localization (MBL) transition in quasiperiodic and random models. Using exact diagonalization we compute the optical conductivity $\sigma(\omega)$ and the return probability $R(\tau)$ and study their average low-frequency and long-time power-law behavior, respectively. We show that the low-energy transport dynamics is markedly distinct in both the thermal and MBL phases in quasiperiodic and random models and find that the diffusive and MBL regimes of the quasiperiodic model are more robust than those in the random system. Using the distribution of the DC conductivity, we quantify the contribution of sample-to-sample and state-to-state fluctuations of $\sigma(\omega)$ across the MBL transition. We find that the activated dynamical scaling ansatz works poorly in the quasiperiodic model but holds in the random model with an estimated activation exponent $\psi\approx 0.9$. We argue that near the MBL transition in quasiperiodic systems, critical eigenstates give rise to a subdiffusive crossover regime on finite-size systems.