Measuring mutual friction in superfluids: the role of initial vortex configuration fluctuations

Fuente: arXiv
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Main Authors: Grani, Nicola, Hernández-Rajkov, Diego, Fernández, Marcia Frómeta, Del Pace, Giulia, Roati, Giacomo
Format: Preprint
Published: 2025
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author Grani, Nicola
Hernández-Rajkov, Diego
Fernández, Marcia Frómeta
Del Pace, Giulia
Roati, Giacomo
author_facet Grani, Nicola
Hernández-Rajkov, Diego
Fernández, Marcia Frómeta
Del Pace, Giulia
Roati, Giacomo
contents The physical origin of mutual friction in quantum fluids is deeply connected to the fundamental nature of superfluidity. It stems from the interaction between the superfluid and normal components, mediated by the dynamics of quantized vortices that induce the exchange of momentum and energy. Despite the complexity of these interactions, their essential features can be effectively described by the dissipative point vortex model, an extension of classical vortex dynamics that incorporates finite-temperature dissipation. Mutual friction is parametrized by the longitudinal (dissipative) coefficient $α$ and the transverse (reactive) coefficient $α'$. Accurate measurement of these parameters provides critical insights into the microscopic mechanisms governing vortex motion and dissipation in quantum fluids, serving as a key benchmark for theoretical models. In this work, we employ the dissipative point vortex model to study how fluctuations in the initial conditions influence the inference of $α$ and $α'$ from the time evolution of the vortex trajectories. Using experimentally realistic parameters, we show that fluctuations can introduce significant biases in the extracted values of the mutual friction coefficients. We compare our findings with recent experimental measurements in strongly interacting atomic superfluids. Applying this analysis to our recent experimental results allowed us to account for fluctuations in the correct determination of $α$ and $α'$.
format Preprint
id arxiv_https___arxiv_org_abs_2508_21546
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Measuring mutual friction in superfluids: the role of initial vortex configuration fluctuations
Grani, Nicola
Hernández-Rajkov, Diego
Fernández, Marcia Frómeta
Del Pace, Giulia
Roati, Giacomo
Quantum Gases
The physical origin of mutual friction in quantum fluids is deeply connected to the fundamental nature of superfluidity. It stems from the interaction between the superfluid and normal components, mediated by the dynamics of quantized vortices that induce the exchange of momentum and energy. Despite the complexity of these interactions, their essential features can be effectively described by the dissipative point vortex model, an extension of classical vortex dynamics that incorporates finite-temperature dissipation. Mutual friction is parametrized by the longitudinal (dissipative) coefficient $α$ and the transverse (reactive) coefficient $α'$. Accurate measurement of these parameters provides critical insights into the microscopic mechanisms governing vortex motion and dissipation in quantum fluids, serving as a key benchmark for theoretical models. In this work, we employ the dissipative point vortex model to study how fluctuations in the initial conditions influence the inference of $α$ and $α'$ from the time evolution of the vortex trajectories. Using experimentally realistic parameters, we show that fluctuations can introduce significant biases in the extracted values of the mutual friction coefficients. We compare our findings with recent experimental measurements in strongly interacting atomic superfluids. Applying this analysis to our recent experimental results allowed us to account for fluctuations in the correct determination of $α$ and $α'$.
title Measuring mutual friction in superfluids: the role of initial vortex configuration fluctuations
topic Quantum Gases
url https://arxiv.org/abs/2508.21546