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arXiv · 2108.12583

Power-Law Random Banded Matrix Ensemble as the Effective Model for Many-Body Localization Transition

Wen-Jia Rao
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Abstract

We employ the power-law random band matrix (PRBM) ensemble with single tuning parameter $\mu $ as the effective model for many-body localization (MBL) transition in random spin systems. We show the PRBM accurately reproduce the eigenvalue statistics on the entire phase diagram through the fittings of high-order spacing ratio distributions $P(r^{(n)})$ as well as number variance $\Sigma ^{2}(l)$, in systems both with and without time-reversal symmetry. For the properties of eigenvectors, it's shown the entanglement entropy of PRBM displays an evolution from volume-law to area-law behavior which signatures an ergodic-MBL transition, and the critical exponent is found to be $\nu =0.83\pm 0.15$, close to the value obtained in 1D physical model by exact diagonalization while the computational cost here is much less.

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Wen-Jia Rao. 2021-08-28. Power-Law Random Banded Matrix Ensemble as the Effective Model for Many-Body Localization Transition. https://doi.org/10.1140/epjp/s13360-022-02621-x

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