Transition from sub-Poissonian to super-Poissonian shot noise in resonant quantum wells

We investigate the transition from sub-Poissonian to super-Poissonian value s of the zero-temperature shot noise power of a resonant double barrier of macroscopic cross section. This transition occurs for driving voltages, whi ch are sufficiently strong to bring the system near an instability threshol d. It is shown that interactions in combination with the energy dependence of the tunneling rates dramatically affect the noise level in such a system . Interaction-induced fluctuations of the band bottom of the well contribut e to the noise and lead to a new energy in the Fano factor. They can enhanc e the noise to super-Poissonian values in a voltage range preceding the ins tability threshold of the system. At low voltages, interactions may either enhance or suppress the noise compared to the noninteracting case. [S016318 29(99)06815-0].