论文标题
动力拓扑与量子淬火中动态噪声的稳定性
Stability of dynamical topology against dynamical noise in quantum quenches
论文作者
论文摘要
平衡拓扑阶段对弱静态障碍具有鲁棒性,但可能在强障碍方面崩溃。在这里,我们探索了在存在动力学噪声的情况下淬灭引起的新兴动力拓扑的稳定性。我们开发了一种分析理论,并表明,对于弱噪声,通过淬灭初始琐碎阶段而引起的量子动力学对Chern绝缘状态造成的量子动力学在某些动量子空间上表现出强大的新兴拓扑结构,称为带反向表面(BISS)。动态拓扑受到biss上最小振荡频率的保护,模仿了动态阶段的宽大间隙。在淬灭动力学中出现奇异性,如果增加噪声到临界强度,表现出动态拓扑过渡,则在biss上的振荡频率最小,超出了这种拓扑的过渡。预测了两种类型的动态转换。有趣的是,当噪声以相同强度为噪声到所有三个自旋组件时,我们预测了临界过渡中的最佳位置,在这种情况下,动态拓扑结构在任意强的噪声状态下生存。这项工作揭示了动力学噪声下动力拓扑的新特征,可以通过实验中的控制探测。
Equilibrium topological phases are robust against weak static disorder but may break down in the strong disorder regime. Here we explore the stability of the quench-induced emergent dynamical topology in the presence of dynamical noise. We develop an analytic theory and show that for weak noise, the quantum dynamics induced by quenching an initial trivial phase to Chern insulating regime exhibits robust emergent topology on certain momentum subspaces called band inversion surfaces (BISs). The dynamical topology is protected by the minimal oscillation frequency over the BISs, mimicking a bulk gap of the dynamical phase. Singularities emerge in the quench dynamics, with the minimal oscillation frequency vanishing on the BISs if increasing noise to critical strength, manifesting a dynamical topological transition, beyond which the emergent topology breaks down. Two types of dynamical transitions are predicted. Interestingly, we predict a sweet spot in the critical transition when noise couples to all three spin components in the same strength, in which case the dynamical topology survives at arbitrarily strong noise regime. This work unveils novel features of the dynamical topology under dynamical noise, which can be probed with control in experiment.