Conditional spin counting statistics as a probe of Coulomb interaction and spin-resolved bunching

TL;DR

This paper introduces the concept of conditional spin counting statistics to analyze mesoscopic transport, demonstrating its effectiveness in probing Coulomb interactions and spin-resolved bunching phenomena in quantum dot systems.

Contribution

It develops a new theoretical framework for conditional spin counting statistics and shows its application in detecting Coulomb interactions and spin-resolved correlations.

Findings

Coulomb interaction significantly alters conditional spin counting statistics.

Conditional statistics can effectively probe Coulomb interactions in quantum dots.

It reveals spin-resolved bunching behavior in spin-polarized transport.

Abstract

Full counting statistics is a powerful tool to characterize the noise and correlations in transport through mesoscopic systems. In this work, we propose the theory of conditional spin counting statistics, i.e., the statistical fluctuations of spin-up (down) current given the observation of the spin-down (up) current. In the context of transport through a single quantum dot, it is demonstrated that a strong Coulomb interaction leads to a conditional spin counting statistics that exhibits a substantial change in comparison to that without Coulomb repulsion. It thus can be served as an effective way to probe the Coulomb interactions in mesoscopic transport systems. In case of spin polarized transport, it is further shown that the conditional spin counting statistics offers a transparent tool to reveal the spin-resolved bunching behavior.