Electronic decoherence along a single nuclear trajectory

TL;DR

This paper introduces a new method to describe subsystem decoherence along a single classical trajectory, capturing non-adiabatic effects without environment tracing, and accurately modeling coherence dynamics where traditional methods fail.

Contribution

The authors develop a novel approach based on the exact factorization framework that describes decoherence along a single trajectory, improving over Ehrenfest dynamics in non-adiabatic scenarios.

Findings

Accurately models coherence gain and decoherence along a nuclear trajectory.

Successfully describes avoided crossing scenarios where Ehrenfest dynamics fails.

Provides a new perspective on subsystem decoherence without environment tracing.

Abstract

We describe a novel approach to subsystem decoherence without the usual tracing-out of the environment. The subsystem of focus is described entirely by a pure state evolving non-unitarily along a single classical trajectory of its environment. The approach is deduced from the exact factorization framework for arbitrary systems of electrons and nuclei. The non-unitarity of the electronic dynamics arises exclusively fromnon-adiabatic correlations between electrons and nuclei. We demonstrate that the approach correctly describes the coherence gain and the subsequent decoherence for the example of a nuclear trajectory passing through an avoided crossing, the prototypical case where single-trajectory Ehrenfest dynamics fails to produce decoherence.