Title: Freezing and Shielding under Global Quenches for Long-Range Interacting Many-Body Systems Show Chinese title

Title: 长程相互作用多体系统在全局淬火下的冻结与屏蔽

Abstract: We investigate the time evolution of a Fermi-Hubbard model with long range hopping following a sudden quench of the local interactions among different spin species. The quasi-particle spectrum consists of gapped low-energy levels while the high energy modes accumulate at a single point. When the low energy gaps are large enough, turning on the local interactions does not effectively mix high and low energy modes, leading to the freezing of the dynamical evolution. In general, the states within the excited subspace are shielded from the long-range signatures of the model, which are responsible for the low energy extended states, and the dynamics effectively look as if long-range hopping were absent. This cooperative shielding mechanism becomes evident in presence of disorder. It is shown that shielding and freezing are a universal feature of long-range interacting systems and conjecture that they are related to the existence of quasi-stationary states. Show Chinese abstract

Abstract: 我们研究了在不同自旋种类之间的局部相互作用突然淬火后，具有长程跃迁的费米-哈伯德模型的时间演化。 准粒子谱由有能隙的低能级组成，而高能模式则集中在一点。 当低能间隙足够大时，开启局部相互作用不会有效混合高能和低能模式，导致动态演化的冻结。 一般来说，激发子空间中的状态被屏蔽，无法感受到模型的长程特征，这些特征负责低能扩展态，因此动力学看起来像是长程跃迁不存在一样。 在存在无序的情况下，这种协同屏蔽机制变得明显。 研究表明，屏蔽和冻结是长程相互作用系统的普遍特性，并推测它们与准稳态的存在有关。