Localization-delocalization transitions in a two-dimensional quantum percolation model: von Neumann entropy studies

Longyan Gong; Peiqing Tong

doi:10.1103/physrevb.80.174205

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arXiv · 0911.5531

Localization-delocalization transitions in a two-dimensional quantum percolation model: von Neumann entropy studies

Longyan Gong·Peiqing Tong

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Abstract

In two-dimensional quantum site-percolation square lattice models, the von Neumann entropy is extensively studied numerically. At a certain eigenenergy, the localization-delocalization transition is reflected by the derivative of von Neumann entropy which is maximal at the quantum percolation threshold $p_q$. The phase diagram of localization-delocalization transitions is deduced in the extrapolation to infinite system sizes. The non-monotonic eigenenergies dependence of $p_q$ and the lowest value $p_q\simeq0.665$ are found. At localized-delocalized transition points, the finite scaling analysis for the von Neumann entropy is performed and it is found the critical exponents $ν$ not to be universal. These studies provide a new evidence that the existence of a quantum percolation threshold $p_q<1$ in the two-dimensional quantum percolation problem.

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BibTeX RIS

Longyan Gong, Peiqing Tong. 2009-11-30. Localization-delocalization transitions in a two-dimensional quantum percolation model: von Neumann entropy studies. https://doi.org/10.1103/physrevb.80.174205

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