论文标题
在二维Clifford电路中没有定位
Absence of localization in two-dimensional Clifford circuits
论文作者
论文摘要
我们在一个和两个空间维度中分析了带有随机Clifford门的Floquet电路。通过使用渗透理论的随机图和方法,我们在两个维度的环境中证明了一些本地操作员以弹道率生长,这意味着没有定位。相反,一维模型显示出强大的定位形式,其特征是随机位置中左和右堵塞壁的出现。我们通过通过对操作员扩散和纠缠增长的数值模拟来补充分析结果来提供其他见解,这表明了二维(一维)中定位的不存在(存在)。此外,我们揭示了二维电路中Floquet统一的频谱形式的表现与混乱的单个粒子动力学的无准费米子的表现,其指数坡道持续到与系统大小相线性缩放。我们的工作阐明了无序,浮雕克利福德动力学的性质及其与完全混乱的量子动态的关系。
We analyze a Floquet circuit with random Clifford gates in one and two spatial dimensions. By using random graphs and methods from percolation theory, we prove in the two dimensional setting that some local operators grow at ballistic rate, which implies the absence of localization. In contrast, the one-dimensional model displays a strong form of localization characterized by the emergence of left and right-blocking walls in random locations. We provide additional insights by complementing our analytical results with numerical simulations of operator spreading and entanglement growth, which show the absence (presence) of localization in two-dimension (one-dimension). Furthermore, we unveil that the spectral form factor of the Floquet unitary in two-dimensional circuits behaves like that of quasi-free fermions with chaotic single particle dynamics, with an exponential ramp that persists till times scaling linearly with the size of the system. Our work sheds light on the nature of disordered, Floquet Clifford dynamics and its relationship to fully chaotic quantum dynamics.