Direct energy dissipation measurements for a driven superfluid via the harmonic-potential theorem
Abstract
We propose and experimentally demonstrate a method to directly measure energy dissipation for a linearly driven superfluid confined in a harmonic trap. The method relies on a perturbed version of the harmonic-potential theorem, according to which a potential perturbation - effectively acting as a stirrer - converts center-of-mass motional energy into internal energy. Energy conservation then enables a direct, quantitative determination of the dissipated energy from measurements of the macroscopic center-of-mass observables. Applying this method to a perturbed, driven Bose-Einstein condensate, we observe dissipation curves characteristic of superfluid flow, including a critical velocity that depends on the stirrer strength, consistent with previous studies. Our results are supported by mean-field simulations, which corroborate both the theoretical framework and the experimental findings.
Cite
@article{arxiv.2508.15626,
title = {Direct energy dissipation measurements for a driven superfluid via the harmonic-potential theorem},
author = {Clara Tanghe and Senne Van Wellen and Kobe Vergaerde and Karel Van Acoleyen},
journal= {arXiv preprint arXiv:2508.15626},
year = {2026}
}
Comments
v2: energy curves now also include the total energy and center-of-mass motional energy, refined analysis of superfluidity in light of local Landau criterion, more detailed study of soliton and phonon production in the mean-field simulations