Anderson L R Barbosa, Diego B Fonseca, Iván R R González, Nathan L Pessoa, Giovani L Vasconcelos, Antônio M S Macêdo
We investigate conductance fluctuations across the integer quantum Hall transition in graphene from the perspective of multiscale stochastic dynamics. Using a tight-binding description combined with the Landauer-Büttiker formalism, we generate longitudinal and transverse transmission time series by sweeping magnetic flux and Fermi energy in disordered nanoribbons with armchair and zigzag terminations. The interplateau regime exhibits non-Gaussian, intermittent fluctuations whose increments display scale dependence and broad-tailed statistics. Multifractal detrended fluctuation analysis reveals a broad singularity spectrum, indicating the coexistence of multiple scaling exponents. To rationalize these features, we model the increment distributions within an H-theory approach that leads to analytical expressions in terms of Meijer G functions, while excellent agreement with the data is achieved by incorporating discrete statistical mixtures that account for clustered variance dynamics. Our results establish a quantitative connection between the quantum Hall transition in graphene and a cascadelike hierarchy in the conductance fluctuations, and clarify the role of disorder in enabling this multiscale regime.