Hidden Phase Transition in Single-Polymer Stretching under Elongational Flow
Abstract
Using machine learning, we identify a second transition in polymer chain stretching driven by planar elongational flow, beyond the well-known coil-stretch transition. We achieve this by developing a conditional extension of Universal and Identifiable Dissipative Dynamics (UIDD) that jointly learns reduced stochastic dynamics from microscopic trajectories across flow strengths and yields the corresponding stationary nonequilibrium free energy landscapes. As the flow strength increases, the evolving landscape exhibits the expected coil-stretch transition, and then a previously unrecognized dynamical transition. In the latter, the stretched states persist, but the distribution along a folding coordinate becomes bimodal when conditioned on small end-to-end separation. Large-deviation analysis of a simplified analytical chain model reproduces both transitions and shows that they are phase transitions in the long-chain limit. Single-molecule DNA experiments provide qualitative support for the dynamical transition through the predicted reversal of the folding response.
Related
- Blockwise friction heterogeneity redistributes stretching in a 2D Gaussian polymer under Batchelor-Kraichnan random flow
- No linear stretching of single-copy quantum pseudorandomness
- Temporal stretching of single-photon pulses by intra-cavity frequency conversion
- Terahertz lattice imprint of a hidden multipolar ordering transition in Gd2Ru2O7
- Generic thermodynamics of condensates with extremely small superfluid density ---Application to UTe2 and hidden second phase transition---
BibTeX
@misc{zhu2026hidden,
title = {{Hidden Phase Transition in Single-Polymer Stretching under Elongational Flow}},
author = {Aiqing Zhu and Fushuai Wang and Eleonore Vissol-Gaudin and Qianxiao Li and Beatrice W. Soh},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.39575},
eprint = {2610.39575},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.39575},
}
RIS
TY - UNPB
TI - Hidden Phase Transition in Single-Polymer Stretching under Elongational Flow
AU - Aiqing Zhu
AU - Fushuai Wang
AU - Eleonore Vissol-Gaudin
AU - Qianxiao Li
AU - Beatrice W. Soh
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2610.39575
UR - https://arxiv.org/abs/2610.39575
AB - Using machine learning, we identify a second transition in polymer chain stretching driven by planar elongational flow, beyond the well-known coil-stretch transition. We achieve this by developing a conditional extension of Universal and Identifiable Dissipative Dynamics (UIDD) that jointly learns reduced stochastic dynamics from microscopic trajectories across flow strengths and yields the corresponding stationary nonequilibrium free energy landscapes. As the flow strength increases, the evolving landscape exhibits the expected coil-stretch transition, and then a previously unrecognized dynamical transition. In the latter, the stretched states persist, but the distribution along a folding coordinate becomes bimodal when conditioned on small end-to-end separation. Large-deviation analysis of a simplified analytical chain model reproduces both transitions and shows that they are phase transitions in the long-chain limit. Single-molecule DNA experiments provide qualitative support for the dynamical transition through the predicted reversal of the folding response.
ER -