Continuous depinning transition with an unusual hysteresis effect

Area of Science:

• Physics
• Condensed Matter Physics
• Statistical Mechanics

Background:

• The depinning transition describes the onset of motion in systems like charge density waves or magnetic domain walls.
• Understanding hysteresis is crucial for characterizing the dynamics and stability of these systems.

Purpose of the Study:

• To identify and characterize a novel hysteresis phenomenon in depinning transition models.
• To investigate the theoretical underpinnings and potential experimental relevance of this hysteresis.

Main Methods:

• Analysis of depinning transition models incorporating both elastic and transient overshoot stresses.
• Exact calculation of the hysteresis gap size in a broad class of models.
• Comparison with continuum field theory and discussion of experimental/numerical signatures.

Main Results:

• A generic, strange hysteresis is identified in depinning models, persisting even in second-order phase transitions.
• The size of the hysteresis gap is calculated exactly for a large family of models.
• This hysteresis, arising from irrelevant perturbations, is absent in the continuum limit's field theory.

Conclusions:

• The identified hysteresis is a real physical phenomenon, distinct from continuum theories.
• This microscopic hysteresis may be responsible for hysteresis observed in natural depinning systems.
• Experimental and numerical investigations, including microscopic nucleation, are proposed to detect this effect.