Experimental observation of spontaneous symmetry breaking in a quantum phase transition

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.

13 pages,9 figures

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Cited by in corpus (6)

• Generating three-photon Rabi oscillations without a large-detuning condition
• Controlling the superradiant phase transition in the quantum Rabi model
• Experimental demonstration of spontaneous symmetry breaking with emergent multi-qubit entanglement
• Nonreciprocal superradiant quantum phase transition induced by the magnon Kerr effect
• An exceptional surface and its topology
• Observing Algebraic Variety of Lee-Yang Zeros in Asymmetrical Systems via a Quantum Probe