# Long-wavelength fluctuations and static correlations in quasi-2D colloidal suspensions

## TL;DR

This study investigates how long-wavelength fluctuations influence the glass transition in quasi-2D colloidal suspensions, revealing the significance of dimensionality and static correlations in 2D supercooled liquids.

## Contribution

It provides experimental evidence linking Mermin-Wagner fluctuations to static correlations and relaxations in 2D colloidal systems, offering new insights into the 2D glass transition.

## Key findings

- Long-wavelength fluctuations increase logarithmically with system size.
- Static correlation length grows in 2D supercooled liquids.
- Mermin-Wagner fluctuations affect translational and orientational relaxations.

## Abstract

Dimensionality strongly affects thermal fluctuations and critical dynamics of equilibrium systems. These influences persist in amorphous systems going through the nonequilibrium glass transition. Here, we experimentally study the glass transition of quasi-2D suspensions of spherical and ellipsoidal particles under different degrees of circular confinement. We show that the strength of the long-wavelength fluctuations increases logarithmically with system sizes and displays the signature of the Mermin-Wagner fluctuations. Moreover, using confinement as a tool, we also measure static structural correlations and extract a growing static correlation length in 2D supercooled liquids. Finally, we explore the influence of the Mermin-Wagner fluctuations on the translational and orientational relaxations of 2D ellipsoidal suspensions, which leads to a new interpretation of the two-step glass transition and the orientational glass phase of anisotropic particles. Our study reveals the importance of long-wavelength fluctuations in 2D supercooled liquids and provides new insights into the role of dimensionality in the glass transition.