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arXiv 2405.03751quant-ph
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多体系统中信号传播的速度极限:量子信息视角

Limits to velocity of signal propagation in many-body systems: a quantum-information perspective

Piotr Wysocki, Jan Chwedeńczuk

AI总结:

本研究从量子信息视角出发,提出通过对连接多体系统的单量子比特进行局部测量来确定Lieb-Robinson界的方法,以单粒子操控替代关联函数测量,并通过XY自旋链验证了该估算方法的有效性。

摘要:

Lieb-Robinson界(LRB,利布-鲁宾逊界)指出,复杂多体系统各组成部分之间相互作用的范围和强度,为信号的传播速度设定了上限。它体现为连接两个远距离子系统的关联函数的类光锥增长。本文采用量子信息技术证明,LRB可通过对与多体系统相连的单个量子比特进行局部测量来确定。这一表述为估算复杂系统中的LRB提供了一种可操作的方案,用简单的单粒子操控替代了关联函数的测量。我们通过推导XY自旋链中信号传播速度的上限,证明了该方法的有效性。

英文摘要:

The Lieb-Robinson bound (LRB) states that the range and strength of interactions between the constituents of a complex many-body system impose upper limits to how fast the signal can propagate. It manifests in a light cone-like growth of correlation function connecting two distant subsystems. Here we employ the techniques of quantum information to demonstrate that the LRB can be determined from local measurements performed on a single qubit that is connected to a many-body system. This formulation provides an operational recipe for estimating the LRB in complex systems, replacing the measurement of the correlation function with simple single-particle manipulations. We demonstrate the potency of this approach by deriving the upper limit to the speed of signal propagation in the XY spin chain.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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