# Lead Geometry and Transport Statistics in Molecular Junctions

## TL;DR

This paper uses the Inchworm quantum Monte Carlo method to study charge transport and fluctuations in molecular junctions, highlighting how lead geometry and finite bandwidth influence transport properties beyond traditional models.

## Contribution

It demonstrates the application of a numerically exact technique to analyze lead geometry effects and reveals interaction-induced broadening of transport channels in molecular junctions.

## Key findings

- Finite lead bandwidth affects transport properties.
- Current fluctuations are more sensitive probes than mean current.
- Interaction-induced broadening is visible at all voltages.

## Abstract

We present a numerically exact study of charge transport and its fluctuations through a molecular junction driven out of equilibrium by a bias voltage, using the Inchworm quantum Monte Carlo (iQMC) method. After showing how the technique can be used to address any lead geometry, we concentrate on one dimensional chains as an example. The finite bandwidth of the leads is shown to affect transport properties in ways that cannot be fully captured by quantum master equations: in particular, we reveal an interaction-induced broadening of transport channels that is visible at all voltages, and show how fluctuations of the current are a more sensitive probe of this effect than the mean current.