Shot noise from action correlations

TL;DR

This paper explains the universal shot noise in ballistic chaotic cavities through action correlations among classical trajectories, revealing a new four-trajectory correlation mechanism that aligns with random-matrix theory.

Contribution

It introduces a novel four-trajectory action correlation mechanism responsible for shot noise, independent of symmetry, validated by quantum graph models and matching RMT predictions.

Findings

Shot noise arises from specific action correlations among trajectories.

Four-trajectory correlations are key to understanding shot noise.

Results agree with random-matrix theory predictions.

Abstract

We consider universal shot noise in ballistic chaotic cavities from a semiclassical point of view and show that it is due to action correlations within certain groups of classical trajectories. Using quantum graphs as a model system we sum these trajectories analytically and find agreement with random-matrix theory. Unlike all action correlations which have been considered before, the correlations relevant for shot noise involve four trajectories and do not depend on the presence of any symmetry.