Quantum percolation in honeycomb lattices under random spin-orbit coupling

Fuente: arXiv
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Main Authors: Oliveira, W. S., Faúndez, Julián, Morgado, Welles
Format: Preprint
Published: 2026
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author Oliveira, W. S.
Faúndez, Julián
Morgado, Welles
author_facet Oliveira, W. S.
Faúndez, Julián
Morgado, Welles
contents We investigate quantum percolation in a honeycomb lattice with site dilution and random spin-orbit coupling. Using exact diagonalization combined with finite-size scaling analysis, we study the metal-insulator transition, extracting the quantum percolation threshold $p_q$, and the correlation-length exponent, $ν$. In the absence of spin-orbit coupling, we find that $p_q$ remains finite and demonstrate that the quantum threshold is significantly higher than the classical site-percolation threshold $p_c$ of the honeycomb lattice. When spin-orbit coupling is present, the spectral statistics exhibit a crossover from the Gaussian orthogonal ensemble to the Gaussian symplectic ensemble, reflecting the change in symmetry class. Simultaneously, the quantum percolation threshold shifts systematically to lower occupation probabilities, indicating that the spin-orbit coupling favors delocalization. For sufficiently strong spin-orbit coupling, $p_q$ tends to saturate, while the critical exponent approaches the expected one of the two-dimensional symplectic universality class.
format Preprint
id arxiv_https___arxiv_org_abs_2604_12732
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Quantum percolation in honeycomb lattices under random spin-orbit coupling
Oliveira, W. S.
Faúndez, Julián
Morgado, Welles
Disordered Systems and Neural Networks
We investigate quantum percolation in a honeycomb lattice with site dilution and random spin-orbit coupling. Using exact diagonalization combined with finite-size scaling analysis, we study the metal-insulator transition, extracting the quantum percolation threshold $p_q$, and the correlation-length exponent, $ν$. In the absence of spin-orbit coupling, we find that $p_q$ remains finite and demonstrate that the quantum threshold is significantly higher than the classical site-percolation threshold $p_c$ of the honeycomb lattice. When spin-orbit coupling is present, the spectral statistics exhibit a crossover from the Gaussian orthogonal ensemble to the Gaussian symplectic ensemble, reflecting the change in symmetry class. Simultaneously, the quantum percolation threshold shifts systematically to lower occupation probabilities, indicating that the spin-orbit coupling favors delocalization. For sufficiently strong spin-orbit coupling, $p_q$ tends to saturate, while the critical exponent approaches the expected one of the two-dimensional symplectic universality class.
title Quantum percolation in honeycomb lattices under random spin-orbit coupling
topic Disordered Systems and Neural Networks
url https://arxiv.org/abs/2604.12732