Spectral density of velocity fluctuations under switching field conditions in graphene

In this paper we present an analysis of the velocity fluctuations during transient regimes arising from an abrupt shift of the electric field in bulk monolayer graphene. For this purpose a material Ensemble Monte Carlo simulator is used to examine these fluctuations by means of the transient autocorrelation function and power spectral density. The evolution of these quantities as well as the non-stationary phenomena taking place during the transients is explained with a microscopic approach. (special issue on unsolved problems of noise in physics, biology and technology)