论文标题
纠缠蔓延和Quasiparticle图片以外的结构
Entanglement spreading and quasiparticle picture beyond the pair structure
论文作者
论文摘要
准粒子图片是一种强大的工具，可以理解淬火后多体量子系统中的纠缠蔓延。作为输入，必须提供初始状态的激发模式的结构，共同的选择是成对创建的激发。但是，有几种情况流放了这个简单的假设。在这项工作中，我们研究了弱相互作用以在一个维度上自由淬火。这会导致更丰富的激发模式，其中具有较大粒子的多重体被激发。我们将准粒子Ansatz推广到如此广泛的初始状态，从而提供了Renyi熵的小耦合膨胀。我们的结果与ITEBD数值模拟完全吻合。
The quasi-particle picture is a powerful tool to understand the entanglement spreading in many-body quantum systems after a quench. As an input, the structure of the excitations' pattern of the initial state must be provided, the common choice being pairwise-created excitations. However, several cases exile this simple assumption. In this work, we investigate weakly-interacting to free quenches in one dimension. This results in a far richer excitations' pattern where multiplets with a larger number of particles are excited. We generalize the quasi-particle ansatz to such a wide class of initial states, providing a small-coupling expansion of the Renyi entropies. Our results are in perfect agreement with iTEBD numerical simulations.
