Département de Physique, Université de Sherbrooke, Québec, Canada.
Phys Rev Lett. 2010 May 14;104(19):190401. doi: 10.1103/PhysRevLett.104.190401. Epub 2010 May 11.
The Lieb-Robinson bound shows the existence of a maximum speed of signal propagation in discrete quantum mechanical systems with local interactions. This generalizes the concept of relativistic causality beyond field theory, and provides a powerful tool in theoretical condensed matter physics and quantum information science. Here, we extend the scope of this seminal result by considering general markovian quantum evolution, where we prove that an equivalent bound holds. In addition, we use the generalized bound to demonstrate that correlations in the stationary state of a Markov process decay on a length scale set by the Lieb-Robinson velocity and the system's relaxation time.
李-罗宾逊界限表明，在具有局部相互作用的离散量子力学系统中存在信号传播的最大速度。这将相对论因果关系的概念推广到超越场论的范围，并为理论凝聚态物理和量子信息科学提供了一个强大的工具。在这里，我们通过考虑一般的马尔可夫量子演化来扩展这个开创性结果的范围，证明了一个等价的界成立。此外，我们利用广义界来证明马尔可夫过程的定态中的相关性以李-罗宾逊速度和系统弛豫时间为标度衰减。
