arXiv:2008.00885 · Physical Review A
Experimental verification of anti–Kibble-Zurek behavior in a quantum system under a noisy control field
Ming-Zhong Ai, Jin‐Ming Cui, Ran He, Zhong-Hua Qian, Xin-Xia Gao, Yun‐Feng Huang, Chuan‐Feng Li, Guang‐Can Guo
Abstract
The Kibble-Zurek (KZ) mechanism is a universal framework that can in principle describe nonequilibrium phase transition phenomena in any system with the required symmetry properties. However, a conflicting phenomenon termed anti-KZ behavior has been reported in the study of ferroelectric phase transitions, in which slower driving results in more topological defects [S. M. Griffin et al., Phys. Rev. X 2, 041022 (2012)]. Although this finding is significant, related experimental work remains scarce. In this work, we experimentally demonstrate anti-KZ behavior under a noisy control field in three different quantum phase transition protocols using a single trapped ${}^{171}{\mathrm{Yb}}^{+}$ ion. The density of defects is studied as a function of the quench time and the noise intensity. We experimentally verify that the optimal quench time to minimize excitations scales as a universal power law of the noise intensity. Our work provides an experimental verification of anti-KZ behavior in a two-level system.