RT Journal Article
SR Electronic
T1 Probing dynamical phase transitions with a superconducting quantum simulator
JF Science Advances
JO Sci Adv
FD American Association for the Advancement of Science
SP eaba4935
DO 10.1126/sciadv.aba4935
VO 6
IS 25
A1 Xu, Kai
A1 Sun, Zheng-Hang
A1 Liu, Wuxin
A1 Zhang, Yu-Ran
A1 Li, Hekang
A1 Dong, Hang
A1 Ren, Wenhui
A1 Zhang, Pengfei
A1 Nori, Franco
A1 Zheng, Dongning
A1 Fan, Heng
A1 Wang, H.
YR 2020
UL http://advances.sciencemag.org/content/6/25/eaba4935.abstract
AB Nonequilibrium quantum many-body systems, which are difficult to study via classical computation, have attracted wide interest. Quantum simulation can provide insights into these problems. Here, using a programmable quantum simulator with 16 all-to-all connected superconducting qubits, we investigate the dynamical phase transition in the Lipkin-Meshkov-Glick model with a quenched transverse field. Clear signatures of dynamical phase transitions, merging different concepts of dynamical criticality, are observed by measuring the nonequilibrium order parameter, nonlocal correlations, and the Loschmidt echo. Moreover, near the dynamical critical point, we obtain a spin squeezing of −7.0 ± 0.8 dB, showing multipartite entanglement, useful for measurements with precision fivefold beyond the standard quantum limit. On the basis of the capability of entangling qubits simultaneously and the accurate single-shot readout of multiqubit states, this superconducting quantum simulator can be used to study other problems in nonequilibrium quantum many-body systems, such as thermalization, many-body localization, and emergent phenomena in periodically driven systems.