Current-carrying molecules: a real space picture

TL;DR

This paper introduces a real-space method to calculate current-voltage characteristics of isolated molecules, modeling them as electrical circuits without explicit lead descriptions, using Lagrange multipliers and dissipated work for potential drops.

Contribution

It presents a novel real-space approach to determine current-voltage curves for molecules, avoiding explicit lead modeling and employing Lagrange multipliers to define the Hamiltonian.

Findings

The method successfully models steady-state DC current in molecules.

Potential profiles across molecules are non-linear, resembling electrical circuits.

The approach provides a new perspective on molecular conduction without explicit leads.

Abstract

An approach is presented to calculate characteristic current vs voltage curves for isolated molecules without explicit description of leads. The Hamiltonian for current-carrying molecules is defined by making resort to Lagrange multipliers, while the potential drop needed to sustain the current is calculated from the dissipated electrical work. Continuity constraints for steady-state DC current result in non-linear potential profiles across the molecule leading, in the adopted real-space picture, to a suggestive analogy between the molecule and an electrical circuit.