Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Max Planck Institute for the Structure and Dynamics of Matter, Center for Free-Electron Laser Science (CFEL), Luruper Chaussee 149, 22761 Hamburg, Germany.
Phys Rev Lett. 2023 Mar 10;130(10):106902. doi: 10.1103/PhysRevLett.130.106902.
Many-body entanglement in condensed matter systems can be diagnosed from equilibrium response functions through the use of entanglement witnesses and operator-specific quantum bounds. Here, we investigate the applicability of this approach for detecting entangled states in quantum systems driven out of equilibrium. We use a multipartite entanglement witness, the quantum Fisher information, to study the dynamics of a paradigmatic fermion chain undergoing a time-dependent change of the Coulomb interaction. Our results show that the quantum Fisher information is able to witness distinct signatures of multipartite entanglement both near and far from equilibrium that are robust against decoherence. We discuss implications of these findings for probing entanglement in light-driven quantum materials with time-resolved optical and x-ray scattering methods.
凝聚态物质系统中的多体纠缠可以通过使用纠缠见证者和特定于算子的量子界来从平衡响应函数中进行诊断。在这里，我们研究了这种方法在探测非平衡量子系统中纠缠态的适用性。我们使用多体纠缠见证者，即量子Fisher 信息，来研究经历库仑相互作用随时间变化的典范费米子链的动力学。我们的结果表明，量子 Fisher 信息能够在远离平衡的情况下见证多体纠缠的明显特征，并且对退相干具有鲁棒性。我们讨论了这些发现对于用光探测光驱动量子材料中的纠缠的影响，方法是使用时间分辨的光学和 X 射线散射方法。
