论文标题
在硬核bose-hubbard梯子中的梯级对定位
Localization of Rung Pairs in Hard-core Bose-Hubbard Ladder
论文作者
论文摘要
在多体系统实验中的量子模拟可能会带来理论上研究的新现象。由最近在超导阶梯电路上进行量子模拟的工作的动机，我们研究了玻色 - 哈伯德阶梯模型的梯级定位，而没有淬火障碍。我们的结果表明，在硬核限制下，在边缘和散装中都存在梯级定位。使用质量框架，可以将两粒子系统映射到具有近似子晶格对称性的有效单粒子系统。在硬核极限的条件下，有效系统被迫在左边缘有缺陷，导致零能量平坦频段，这是rung-pair定位的起源。我们还研究了Bose-Hubbard Ladder模型的多粒子动力学，这超出了单粒子图片。在这种情况下，我们发现尽管对之间存在相互作用，但仍可以生存。此外，数值结果表明，纠缠熵表现出长期对数增长，饱和值满足了体积定律。这种现象意味着这种相互作用在动态过程中起着重要作用，尽管它不能打破本地化。我们的结果揭示了与零能量平坦带有关的另一种有趣的无疾病定位，该频带是由现场相互作用和特定的晶格对称性引起的。
Quantum simulation in experiments of many-body systems may bring new phenomena which are not well studied theoretically. Motivated by a recent work of quantum simulation on a superconducting ladder circuit, we investigate the rung-pair localization of the Bose-Hubbard ladder model without quenched disorder. Our results show that, in the hard-core limit, there exists a rung-pair localization both at the edges and in the bulk. Using center-of-mass frame, the two-particle system can be mapped to an effective single-particle system with an approximate sub-lattice symmetry. Under the condition of hard-core limit, the effective system is forced to have a defect at the left edge leading to a zero-energy flat band, which is the origin of the rung-pair localization. We also study the multi-particle dynamics of the Bose-Hubbard ladder model, which is beyond the singleparticle picture. In this case, we find that the localization can still survive despite of the existence of interaction between the pairs. Moreover, the numerical results show that the entanglement entropy exhibits a long-time logarithmic growth and the saturated values satisfy a volume law. This phenomenon implies that the interaction plays an important role during the dynamics, although it cannot break the localization. Our results reveal another interesting type of disorder-free localization related to a zero-energy flat band, which is induced by on-site interaction and specific lattice symmetry.
