部分投影系综揭示慢速倾斜约束信息传播
Partial projected ensembles reveal slow tilt-constrained information spreading
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中文总结 AI 辅助
本研究通过部分投影系综，在 kicked Ising 链中揭示倾斜约束导致信息传播显著延迟，并区分了关联发展时间与部分观测下可访问信息。
中文摘要 AI 辅助
投影系综揭示了超越约化密度矩阵的量子多体动力学信息。在此，我们研究空间约束如何影响具有空间变化纵向场的 kicked Ising 链中这些信息的涌现。我们考虑部分投影系综，通过测量一个远程区域而让中间的缓冲区域不被观测来获得。我们的数值结果揭示了遍历区中近弹道关联起始与倾斜约束区中强烈延迟起始之间的显著对比，并通过量子互信息得到证实。尽管这些起始尺度不同，条件态涨落在两个区域中都随缓冲长度近似指数衰减。完整投影系综还表现出缓慢弛豫及其高阶矩中持续的测量基依赖性。我们建立了连通二阶矩的信息论表征，并使用具有有效基测量的可解退相模型来说明相位累积与相干性损失的分离。在该模型中，阶乘抑制的耦合包络产生亚对数传播，与有限距离起始趋势一致。我们的结果将部分投影系综识别为区分关联发展所需时间与部分观测下仍可访问信息之间差异的探针。
英文摘要
Projected ensembles reveal information about quantum many-body dynamics beyond the reduced density matrix. Here we investigate how spatial constraints affect the emergence of this information in a kicked Ising chain with a spatially varying longitudinal field. We consider partial projected ensembles, obtained by measuring a remote region while leaving an intervening buffer unobserved. Our numerical results reveal a pronounced contrast between nearly ballistic correlation onset in the ergodic regime and strongly delayed onset in the tilt-constrained regime, corroborated by quantum mutual information. Despite these different onset scales, the conditional-state fluctuations decrease approximately exponentially with buffer length in both regimes. Full projected ensembles additionally exhibit slow relaxation and persistent measurement-basis dependence in their higher moments. We establish an information-theoretic characterization of the connected second moment and use a solvable dephasing model with effective-basis measurements to illustrate the separation of phase accumulation and coherence loss. Within this model, a factorially suppressed coupling envelope yields sublogarithmic spreading consistent with the finite-distance onset trends. Our results identify partial projected ensembles as probes of the distinction between the time required for correlations to develop and the information that remains accessible under partial observation.
发表机构
- Institute for Quantum Science and Technology, Shanghai University（上海大学量子科学与技术研究院）
- School of Physics and Optoelectronics, Xiangtan University（湘潭大学物理与光电工程学院）
- Department of Physics, National University of Singapore（新加坡国立大学物理系）
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