The measured speed in the evanescent regime reflects the spatial decay of the wavefunction, not particle motion

TL;DR

The paper clarifies that the measured speed in evanescent regimes reflects wavefunction decay, not particle velocity, aligning with Bohmian mechanics and resolving misconceptions about quantum particle motion.

Contribution

It clarifies the operational meaning of the parameter v in Bohmian mechanics, emphasizing it as a wavefunction gradient, not particle velocity, and corrects misinterpretations from recent experiments.

Findings

The measured parameter v reflects wavefunction decay, not particle speed.

The experiment supports the wave-particle separation in Bohmian mechanics.

Misinterpretations of v as particle velocity are addressed and corrected.

Abstract

The recent paper by Sharoglazova et al. reports an energy-dependent parameter $\nu$ extracted from the spatial distribution of photons in a coupled-waveguide experiment. The authors interpret $\nu$ as the speed of quantum particles, even in the classically forbidden regime, and claim that its finite value contradicts the Bohmian mechanics prediction of zero particle velocity. This challenge arises from a fundamental misunderstanding of the operational meaning of v within the Bohmian ontological framework. We demonstrate that v quantifies the spatial gradient of the wavefunctions amplitude, a geometric property of the guiding field, not the kinematical velocity of point-like particles. The experiment therefore does not challenge but rather illustrates the clean ontological separation between the wave and particle aspects inherent to Bohmian mechanics.