The Kibble–Zurek mechanism (KZM) describes the dynamics across a phase transition leading to the formation of topological defects, such as vortices in superfluids and domain walls in spin systems. Here, we experimentally probe the distribution of kink pairs in a one-dimensional quantum Ising chain driven across the paramagnet-ferromagnet quantum phase transition, using a single trapped ion as a quantum simulator in momentum space. The number of kink pairs after the transition follows a Poisson binomial distribution, in which all cumulants scale with a universal power law as a function of the quench time in which the transition is crossed. We experimentally verified this scaling for the first cumulants and report deviations due to noise-induced dephasing of the trapped ion. Our results establish that the universal character of the critical dynamics can be extended beyond KZM, which accounts for the mean kink number, to characterize the full probability distribution of topological defects.

Kibble-Zurek机理（KZM）描述了相变过程中的动力学，该动力学导致拓扑缺陷的形成，例如超流体中的涡旋和自旋系统中的畴壁。在这里，我们使用单个俘获离子作为动量空间中的量子模拟器，实验性地研究了跨顺磁体-铁磁体量子相变驱动的一维量子伊辛链中扭结对的分布。过渡之后的扭结对数遵循泊松二项式分布，其中所有累积量均以通用幂定律进行缩放，该函数是过渡经过的淬灭时间的函数。我们通过实验验证了第一个累积量的缩放比例，并报告了由于噪声引起的捕获离子移相而产生的偏差。