Observation of Many-Body Quantum Phase Transitions beyond the Kibble-Zurek Mechanism

Quantum critical behavior of many-body phase transitions is one of the most fascinating yet challenging questions in quantum physics. Here, we improved the band-mapping method to investigate the quantum phase transition from superfluid to Mott insulators, and we observed the critical behaviors of quantum phase transitions in both the dynamical steady-state-relaxation region and the phase-oscillation region. Based on various observables, two different values for the same quantum critical parameter are observed. This result is beyond a universal-scaling-law description of quantum phase transitions known as the Kibble-Zurek mechanism, and suggests that multiple quantum critical mechanisms are competing in many body quantum phase transition experiments in inhomogeneous systems.

Automated summary

In this study, the band-mapping method was improved to investigate the quantum phase transition from superfluid to Mott insulators, revealing different critical behaviors. The findings suggest the presence of multiple competing quantum critical mechanisms in many body quantum phase transition experiments.