NONEQUILIBRIUM THERMAL NOISE IN GAAS GAALAS SUPERLATTICE MINIBAND/

We present the first measurement of non-equilibrium thermal noise (i.e . hot electron diffusion noise) related to vertical transport in super lattice minibands. Bias dependence of the longitudinal diffusion coeff icient has been extracted from experimental data and compared with two models, We show that this coefficient is a clearly decreasing functio n of the applied electric field, in agreement with theoretical models. This result highlights the potential superiority of superlattices in millimeter wave devices as regards noise. (C) 1996 American Institute of Physics.