Desaules Jean-Yves, Pietracaprina Francesca, Papić Zlatko, Goold John, Pappalardi Silvia
School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom.
Department of Physics, Trinity College Dublin, D02PN40 Dublin 2, Ireland.
Phys Rev Lett. 2022 Jul 8;129(2):020601. doi: 10.1103/PhysRevLett.129.020601.
Recent experimental observation of weak ergodicity breaking in Rydberg atom quantum simulators has sparked interest in quantum many-body scars-eigenstates which evade thermalization at finite energy densities due to novel mechanisms that do not rely on integrability or protection by a global symmetry. A salient feature of some quantum many-body scars is their subvolume bipartite entanglement entropy. In this Letter, we demonstrate that such exact many-body scars also possess extensive multipartite entanglement structure if they stem from an su(2) spectrum generating algebra. We show this analytically, through scaling of the quantum Fisher information, which is found to be superextensive for exact scarred eigenstates in contrast to generic thermal states. Furthermore, we numerically study signatures of multipartite entanglement in the PXP model of Rydberg atoms, showing that extensive quantum Fisher information density can be generated dynamically by performing a global quench experiment. Our results identify a rich multipartite correlation structure of scarred states with significant potential as a resource in quantum enhanced metrology.
最近在里德堡原子量子模拟器中对弱遍历性破坏的实验观测引发了人们对量子多体伤疤本征态的兴趣，这些本征态由于不依赖可积性或全局对称性保护的新机制，在有限能量密度下规避热化。一些量子多体伤疤的一个显著特征是它们的子体积二分纠缠熵。在本信函中，我们证明，如果此类精确的多体伤疤源于一个(su(2))谱生成代数，那么它们也具有广泛的多体纠缠结构。我们通过量子费舍尔信息的标度分析证明了这一点，结果发现对于精确的伤疤本征态，量子费舍尔信息是超广延的，这与一般的热态形成对比。此外，我们对里德堡原子的PXP模型中的多体纠缠特征进行了数值研究，结果表明通过进行全局猝灭实验可以动态地产生广泛的量子费舍尔信息密度。我们的结果确定了伤疤态丰富的多体关联结构，其作为量子增强计量学中的一种资源具有巨大潜力。
