Reduction of shot noise in superlattice structures by nonequilibrium Green’s function calculations

Abstract

Recent measurements show the superlattice shot noise Fano factor in a low field limit will not universally approach 1/3 as previously predicted. We theoretically investigate the superlattice shot noise behaviors based on the nonequilibrium Green's function method. It is demonstrated that the shot noise reduction reflects the intrinsic nature of superlattice transport pictures. At low field limit, the Fano factor is reduced to a lower value by sweeping the superlattice from the sequential tunneling to miniband conduction regime via decreasing the barrier width. At high field, the superlattice is in the Wannier-Stark hopping regime and the shot noise will asymptotically approach the full Poisson value. These theoretically obtained superlattice shot noise behaviors show good qualitative agreement with the recent experimental observations.