The shot noise in a quantum ring, connected to leads, is studied in the presence of electron interactions in the sequential tunneling regime. Two qualitatively different noise correlations with distinctly different behaviors are identified and studied in a large range of parameters. Noise in the total current is due to the discreteness of the electron charge and can become super-Poissonian as a result of electron interaction. The noise in the magnetization current is comparatively insensitive to the interaction but can be greatly enhanced if an inversion of the populating ratio of the angular states is assumed. The characteristic time scales are studied by a Monte Carlo simulation.

• Received 10 December 2004

DOI:https://doi.org/10.1103/PhysRevB.71.235325