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arXiv · 1903.01764

Quantum to classical crossover under dephasing effects in a two-dimensional percolation model

Junjie Qi·Haiwen Liu·Chui-zhen Chen·Hua Jiang·X. C. Xie
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Abstract

Scaling theory predicts complete localization in $d=2$ in quantum systems belonging to orthogonal class (i.e. with time-reversal symmetry and spin-rotation symmetry). The conductance $g$ behaves as $g \sim exp(-L/l)$ with system size $L$ and localization length $l$ in the strong disorder limit. However, classical systems can always have metallic states in which Ohm's law shows a constant $g$ in $d=2$. We study a two-dimensional quantum percolation model by controlling dephasing effects. The numerical investigation of $g$ aims at simulating a quantum-to-classical percolation evolution. An unexpected metallic phase, where $g$ increases with $L$, generates immense interest before the system becomes completely classical. Furthermore, the analysis of the scaling plot of $g$ indicates a metal-insulator crossover.

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Junjie Qi, Haiwen Liu, Chui-zhen Chen, Hua Jiang, X. C. Xie. 2019-03-05. Quantum to classical crossover under dephasing effects in a two-dimensional percolation model. https://arxiv.org/abs/1903.01764

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