Long range correlations generated by phase separation. Exact results from field theory

TL;DR

This paper uses field theory to derive exact results showing how phase separation in near-critical planar systems creates long-range correlations along interfaces, contrasting with exponential decay in pure phases.

Contribution

It provides the first exact analytic derivation of long-range correlations induced by phase separation in near-critical systems using field theory.

Findings

Long-range correlations are generated along interfaces due to phase separation.

Explicit analytic form of correlations is derived.

Contributions to the interface structure factor are identified.

Abstract

We consider near-critical planar systems with boundary conditions inducing phase separation. While order parameter correlations decay exponentially in pure phases, we show by direct field theoretical derivation how phase separation generates long range correlations in the direction parallel to the interface, and determine their exact analytic form. The latter leads to specific contributions to the structure factor of the interface.