Fernando Javier Gómez-Ruiz

Experimentally testing quantum critical dynamics beyond the Kibble-Zurek mechanism

Jin-Ming Cui [1,2,3,4,6], Fernando Javier Gómez-Ruiz, Yun-Feng Huang [1,2], Chuan-Feng Li [1,2], Guang-Can Guo [1,2], Adolfo del Campo [3,5,6,7]

Abstract

We experimentally probe the distribution of kink pairs resulting from driving a one-dimensional quantum Ising chain through 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 the paradigmatic Kibble-Zurek mechanism, which accounts for the mean kink number, to characterize the full probability distribution of topological defects.