Sinha Sudip, Sinha S
Indian Institute of Science Education and Research-Kolkata, Mohanpur, Nadia 741246, India.
Phys Rev Lett. 2020 Sep 25;125(13):134101. doi: 10.1103/PhysRevLett.125.134101.
We consider a model describing Bose-Josephson junction (BJJ) coupled to a single bosonic mode exhibiting quantum phase transition (QPT). Onset of chaos above QPT is observed from semiclassical dynamics as well from spectral statistics. Based on entanglement entropy, we analyze the ergodic behavior of eigenstates with increasing energy density which also reveals the influence of dynamical steady state known as π-mode on it. We identify the imprint of unstable π-oscillation as many body quantum scar (MBQS), which leads to the deviation from ergodicity and quantify the degree of scarring. Persistence of phase coherence in nonequilibrium dynamics of such initial state corresponding to the π-mode is an observable signature of MBQS which has relevance in experiments on BJJ.
我们考虑一个描述与单个玻色子模式耦合的玻色 - 约瑟夫森结（BJJ）的模型，该模型呈现量子相变（QPT）。从半经典动力学以及谱统计中都观察到了高于QPT时混沌的出现。基于纠缠熵，我们分析了随着能量密度增加本征态的遍历行为，这也揭示了被称为π模式的动态稳态对其的影响。我们将不稳定π振荡的印记识别为多体量子疤痕（MBQS），它导致了与遍历性的偏差并量化了疤痕程度。对应于π模式的这种初始态在非平衡动力学中的相位相干持续性是MBQS的一个可观测特征，这在BJJ实验中具有相关性。
