Noise correlations in a Coulomb-blockaded quantum dot

Phys Rev Lett. 2007 Jul 20;99(3):036603. doi: 10.1103/PhysRevLett.99.036603. Epub 2007 Jul 20.

Abstract

We report measurements of current noise auto- and cross correlation in a tunable quantum dot with two or three leads. As the Coulomb blockade is lifted at finite source-drain bias, the autocorrelation evolves from super- to sub-Poissonian in the two-lead case, and the cross correlation evolves from positive to negative in the three-lead case, consistent with transport through multiple levels. Cross correlations in the three-lead dot are found to be proportional to the noise in excess of the Poissonian value in the limit of weak output tunneling.