Normal and Anomalous Diffusion in Soft Lorentz Gases
Rainer Klages1,2,3, Sol Selene Gil Gallegos1, Janne Solanpää4
1Queen Mary University of London, School of Mathematical Sciences, Mile End Road, London E1 4NS, United Kingdom.
Physical Review Letters
|March 2, 2019
Summary
We investigated particle diffusion in a soft Lorentz gas on a triangular lattice. Results show normal and anomalous diffusion highly sensitive to parameters, differing from hard disk models.
Area of Science:
- Condensed matter physics
- Statistical mechanics
- Computational physics
Background:
- Electronic transport in graphenelike structures.
- Conventional periodic Lorentz gas models with hard disks.
Purpose of the Study:
- To study classical particle diffusion in Fermi potentials on a triangular lattice.
- To analyze the behavior of a soft Lorentz gas system.
- To compare diffusion in soft versus hard scatterer systems.
Main Methods:
- Computational analysis of particle trajectories.
- Modeling diffusion with Fermi potentials on a triangular lattice.
- Investigating parameter space for orbit characteristics.
Main Results:
- Observed both normal and anomalous (super)diffusion.
- Demonstrated extreme sensitivity to model parameters.
- Identified tonguelike structures in parameter space indicating trapped and ballistic orbits.
Conclusions:
- Soft potentials lead to diffusion behaviors distinct from hard disk Lorentz gases.
- The diffusion in soft Lorentz gases is not robust and highly parameter-dependent.
- Findings challenge assumptions about diffusion in paradigmatic hard Lorentz gas models.
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