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Non-monotonic magnetic friction from collective rotor dynamics
Hongri Gu1,2, Anton Lüders3,4, Clemens Bechinger5
1Division of Integrative Systems and Design, Hong Kong University of Science and Technology, Hong Kong, China. hongrigu@ust.hk.
Nature Materials
|March 19, 2026
Summary
Friction arises from magnetic dynamics, not just load. Competing magnetic interactions create a non-monotonic friction dependence on separation, enabling new contactless control possibilities.
Area of Science:
- Condensed Matter Physics
- Tribology
- Magnetism
Background:
- Amontons' law describes friction as load-dependent.
- This law fails when internal degrees of freedom are significant.
Purpose of the Study:
- To demonstrate friction emerging from magnetic configurational dynamics.
- To investigate the relationship between magnetic interactions and friction.
Main Methods:
- Sliding a 2D array of magnetic moments over a magnetic substrate.
- Observing friction dependence on interlayer separation.
- Utilizing molecular dynamics simulations and a two-sublattice model.
Main Results:
- Observed non-monotonic friction dependence on interlayer separation.
- Friction peaks due to competing ferromagnetic/antiferromagnetic interactions and hysteresis.
- Dissipation is governed by collective magnetic reorientations.
Conclusions:
- Magnetic order changes during sliding impact friction significantly.
- Potential for contactless friction control and novel magnetic materials.
- Opens possibilities for wear-free interfaces and magnetic sensing.
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