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arXiv · 2603.02966

Nuclear interference by electronic de-orthogonalisation

Matisse Wei-Yuan Tu·Angel Rubio·E. K. U. Gross
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Abstract

Interference is a universal consequence of superposition, yet in composite quantum systems it can encode correlations between subsystems. We show that in coupled electron-nuclear dynamics, interference in the nuclear density can arise dynamically even when it is initially absent. Starting from a superposition of orthogonal Born-Oppenheimer electronic states, we demonstrate within the exact factorisation framework that genuine non-adiabatic electron-nuclear correlations induce de-orthogonalisation of the electronic factors, thereby generating interference terms in the nuclear density. Such interference has no counterpart in adiabatic evolution. Unlike conventional nuclear wave-packet interference or interference that merely reflects electronic coherence in a chosen basis, the effect identified here is a manifestation of the compositeness of the full electron-nuclear state. Nuclear density interference thus emerges as a direct dynamical signature of correlated quantum motion in composite systems.

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Matisse Wei-Yuan Tu, Angel Rubio, E. K. U. Gross. 2026-03-03. Nuclear interference by electronic de-orthogonalisation. https://arxiv.org/abs/2603.02966

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