Experimental observation of spontaneous symmetry breaking in a quantum phase transition  

作　　者：Wen Ning Ri-Hua Zheng Jia-Hao Lu Fan Wu Zhen-Biao Yang Shi-Biao Zheng 

机构地区：[1]Fujian Key Laboratory of Quantum Information and Quantum Optics,College of Physics and Information Engineering,Fuzhou University,Fuzhou 350108,China [2]Hefei National Laboratory,Hefei 230088,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2024年第2期34-39,共6页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.11874114,12274080,and 11875108);the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0300200)。

摘　　要：Spontaneous symmetry breaking(SSB)plays a central role in understanding a large variety of phenomena associated with phase transitions,such as superfluid and superconductivity.So far,the transition from a symmetric vacuum to a macroscopically ordered phase has been substantially explored.The process bridging these two distinct phases is critical to understanding how a classical world emerges from a quantum phase transition,but so far remains unexplored in experiment.We here report an experimental demonstration of such a process with a quantum Rabi model engineered with a superconducting circuit.We move the system from the normal phase to the superradiant phase featuring two symmetry-breaking field components,one of which is observed to emerge as the classical reality.The results demonstrate that the environment-induced decoherence plays a critical role in the SSB.

关 键 词：quantum phase transition Rabi model spontaneous symmetry breaking superconducting circuit Schrodinger cat states 

分 类 号：O413[理学—理论物理]