论文标题
具有自发对称性破坏的二维量子顺序中拓扑缺陷和纹理的理论
Theory of topological defects and textures in two-dimensional quantum orders with spontaneous symmetry breaking
论文作者
论文摘要
我们考虑具有远距离顺序的二维(2D)量子多体系统,其中光谱中唯一的无间隙激发是自发断裂的连续对称性的金石模式。为了了解局部顺序参数的经典远程顺序与地面状态下的远程纠缠的量子顺序之间的相互作用,我们研究了此类系统中有序参数的拓扑点缺陷和纹理。我们表明,点缺陷和纹理的通用性能取决于具有非泄漏顺序参数的对称性基线状态中的残留对称性拓扑顺序,并基于通货膨胀范围的精确序列为其性质提供了分类。我们重点介绍了我们的理论框架揭示的一些现象。首先,在没有固有拓扑顺序的情况下,我们显示了点缺陷的对称特性与纹理与固定量子临界点之间的联系。其次,当破坏对称的基态具有内在的拓扑顺序时,我们表明,在编织时,点缺陷可能会置于不同的人。他们还可以从某种意义上遵守投射融合规则,即多个涡流可以将其融合到Abelian Anyon中,这是我们“缺陷分数化”的现象。最后,我们提供了一个公式,以计算亚伯式拓扑顺序中纹理(Skyrmions)携带的分数统计数据和分数量子数。
We consider two-dimensional (2d) quantum many-body systems with long-range orders, where the only gapless excitations in the spectrum are Goldstone modes of spontaneously broken continuous symmetries. To understand the interplay between classical long-range order of local order parameters and quantum order of long-range entanglement in the ground states, we study the topological point defects and textures of order parameters in such systems. We show that the universal properties of point defects and textures are determined by the remnant symmetry enriched topological order in the symmetry-breaking ground states with a non-fluctuating order parameter, and provide a classification for their properties based on the inflation-restriction exact sequence. We highlight a few phenomena revealed by our theory framework. First, in the absence of intrinsic topological orders, we show a connection between the symmetry properties of point defects and textures to deconfined quantum criticality. Second, when the symmetry-breaking ground state have intrinsic topological orders, we show that the point defects can permute different anyons when braided around. They can also obey projective fusion rules in the sense that multiple vortices can fuse into an Abelian anyon, a phenomena for which we coin "defect fractionalization". Finally, we provide a formula to compute the fractional statistics and fractional quantum numbers carried by textures (skyrmions) in Abelian topological orders.