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Updated: Jul 15, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Thermal diffusion of solitons on anharmonic chains with long-range coupling
C Brunhuber1, F G Mertens, Y Gaididei
1Physikalisches Institut, Universität Bayreuth, D-95440 Bayreuth, Germany. Christian.Brunhuber@uni-bayreuth.de
Summary
Nontopological solitons exhibit superdiffusive thermal diffusion in anharmonic chains, even with long-range interactions. This behavior, driven by nearest-neighbor interactions, is a general characteristic of these solitons.
Area of Science:
- Condensed Matter Physics
- Nonlinear Dynamics
- Statistical Mechanics
Background:
- Studies on thermal diffusion of nontopological solitons are extended to more complex systems.
- Anharmonic Fermi-Pasta-Ulam-type chains with long-range couplings are investigated.
Purpose of the Study:
- To analyze the thermal diffusion of nontopological solitons in anharmonic chains with long-range interactions.
- To determine the dominant mechanism driving soliton diffusion in these systems.
Main Methods:
- Collective variable (CV) technique within variational analysis for continuum approximation.
- Derivation of stochastic integrodifferential equations for soliton position and inverse width.
- Reduction to statistically equivalent Langevin-type equations and comparison with discrete system simulations.
Main Results:
- Superdiffusive behavior, previously observed in nearest-neighbor interactions, dominates soliton diffusion even with long-range couplings.
- Langevin equation solutions and discrete system simulations show good agreement.
- The variance of the soliton increases non-linearly with time, confirming superdiffusion.
Conclusions:
- Superdiffusion is a robust and generic feature of nontopological solitons in anharmonic chains, irrespective of interaction range.
- The findings reinforce the conjecture of superdiffusion being a general characteristic of nontopological solitons.
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