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arXiv · 2406.19624

Experimental observation of spontaneous symmetry breaking in a quantum phase transition

Wen Ning·Ri-Hua Zheng·Jia-Hao Lü·Fan Wu·Zhen-Biao Yang·Shi-Biao Zheng
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Abstract

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.

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Wen Ning, Ri-Hua Zheng, Jia-Hao Lü, Fan Wu, Zhen-Biao Yang, Shi-Biao Zheng. 2024-06-28. Experimental observation of spontaneous symmetry breaking in a quantum phase transition. https://doi.org/10.1007/s11433-023-2259-1

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