Positive current correlations associated with super-Poissonian shot noise

Phys Rev Lett. 2006 Aug 11;97(6):066604. doi: 10.1103/PhysRevLett.97.066604. Epub 2006 Aug 11.

Abstract

We report on shot noise cross spectrum measurements in a beam splitter configuration. Electrons tunneling through potential barriers are incident on a beam splitter and scattered into two separate channels. Such a partition process introduces correlations between the fluctuations of the two currents. Our work has confirmed that the generally expected negative correlations resulted from sub-Poissonian electron sources. More interestingly, positive cross correlations associated with barriers exhibiting super-Poissonian shot noise have also been observed. We have found that both positive and negative correlations can be related to the noise properties of the electron source.