A simple understanding of quantum electrodynamics using Bohmian trajectories: detecting non-ontic photons

TL;DR

This paper demonstrates how Bohmian trajectories can model quantum electrodynamics phenomena, including photon creation and annihilation, providing a clear, computational, and pedagogical framework for understanding quantum optics.

Contribution

It rehabilitates Bohmian mechanics for quantum optics, showing how to model photons and electromagnetic fields with trajectories, clarifying measurement and non-ontic elements.

Findings

Bohmian trajectories can model photon creation and annihilation.

The framework reproduces experimental results like partition noise.

It clarifies the meaning of measuring non-ontic electromagnetic properties.

Abstract

The use of Bohmian mechanics as a practical tool for modeling non-relativistic quantum phenomena of matter provides clear evidence of its success, not only as a way to interpret the foundations of quantum mechanics, but also as a computational framework. In the literature, it is frequently argued that such a realistic view-based on deterministic trajectories cannot account for phenomena involving the "creation" and "annihilation" of photons. In this paper, by revisiting and rehabilitating earlier proposals, we show how quantum optics can be modeled using Bohmian trajectories for electrons in physical space, together with well-defined electromagnetic fields evolving in time. By paying special attention to an experiment demonstrating partition noise for photons, and to how the Born rule emerges in this context, the paper pursues two main goals. First, it vindicates the pedagogical use of this simple Bohmian framework to compute, understand, and visualize quantum electrodynamics phenomena. Second, given that measurements are ultimately indicated on matter pointers, it clarifies what it means to measure photon or electromagnetic-field properties, even when they are considered non-ontic elements.