The "Coulomb phase" in frustrated systems

TL;DR

This paper reviews the Coulomb phase in frustrated lattice systems, highlighting emergent gauge fields, defect interactions, and characteristic correlations, with applications to magnetic phenomena, quantum effects, phase transitions, and disorder.

Contribution

It provides a comprehensive survey of the theoretical framework, correlation functions, and experimental signatures of the Coulomb phase in frustrated systems.

Findings

Power-law correlation functions derived

Pinch-point features in reciprocal space identified

Implications for magnetic relaxation and phase transitions

Abstract

The "Coulomb phase" is an emergent state for lattice models (particularly highly frustrated antiferromagnets) which have local constraints that can be mapped to a divergence-free "flux". The coarse-grained version of this flux or polarization behave analogously to electric or magnetic fields; in particular, defects at which the local constraint is violated behave as effective charges with Coulomb interactions. I survey the derivation of the characteristic power-law correlation functions and the pinch-points in reciprocal space plots of diffuse scattering, as well as applications to magnetic relaxation, quantum-mechanical generalizations, phase transitions to long-range-ordered states, and the effects of disorder.