Spatiotemporal correlation of conduction current fluctuations within a hydrodynamic-Langevin scheme

We present a hydrodynamic-Langevin scheme to describe electronic noise in u nipolar structures and evaluate the cross-correlation functions of conducti on current fluctuations entering the transfer impedance method. The theory is developed in terms of microscopic fluctuations of carrier velocity and e nergy taking place during scattering events. Applications to submicron n(+) nn(+) GaAs structures show that the contribution of stochastic velocity ra te prevails over that of the energy rate in determining the cross-correlati on function of conduction current fluctuations. (C) 1999 American Institute of Physics. [S0003-6951(99)01105-5].