Second spectrum of 1 / f noise due to mobility fluctuations:Simulations vs experiments in suspended graphene

Mobility fluctuations have been observed to influence 1 / f noise in mesoscopic two-dimensional conductors in recent experiments. If such mobility noise can be assigned to clustering/declustering of defects/impurities, the second spectrum should also display 1 / f character. In this work, we investigate the second spectrum of noise due to mobile impurities on a two-dimensional lattice both using kinetic Monte Carlo simulations (periodic boundary conditions either in one or two directions) and experiments on suspended graphene in Corbino geometry. The simulations indicate 1 / f δ behavior with δ ≃ 0.8 ± 0.15 for the second spectrum of noise, while the experiments on suspended graphene yield an exponent δ ≃ 0.7 ± 0.3 , independent of the amount of adsorbed atoms.