Nonequilibrium strongly hyperuniform fluids of circle active particles with large local density fluctuations

Area of Science:

• Condensed Matter Physics
• Materials Science
• Statistical Mechanics

Background:

• Disordered hyperuniform structures are exotic states of matter with suppressed long-wavelength density fluctuations, resembling crystals but lacking long-range order.
• The rational design of experimentally realizable disordered strongly hyperuniform microstructures remains a significant challenge in materials science.

Purpose of the Study:

• To identify and characterize a new type of nonequilibrium fluid exhibiting strong hyperuniformity.
• To explore the underlying mechanisms responsible for hyperuniformity in systems of chiral active particles.

Main Methods:

• Investigated two-dimensional systems composed of chiral active particles with identical handedness circular motion.
• Developed and applied a dynamic mean-field theory to analyze the system's behavior.

Main Results:

• Identified a novel hyperuniform fluid in chiral active particle systems.
• Observed a characteristic length scale (particle trajectory diameter) below which significant density fluctuations occur.
• Attributed local density fluctuations to motility-induced microphase separation.

Conclusions:

• The global hyperuniformity arises from Fickian diffusion at large length scales and local center-of-mass-conserved noises.
• This discovery provides a new avenue for designing disordered hyperuniform materials with tunable properties.