High-Temperature Phase Separation and Charge-Magnon Liquid in Kinetic Antiferromagnets

TL;DR

This paper reveals how kinetic antiferromagnetism on a triangular lattice leads to high-temperature phase separation and the formation of a strongly bound charge-magnon liquid, providing insights into quantum ordering in correlated systems.

Contribution

It demonstrates, through large-scale simulations, that charge-magnon interactions induce phase separation and a bound liquid state in kinetic antiferromagnets, connecting theory with recent experimental observations.

Findings

High-temperature phase separation into charge- and magnon-rich regions.

Formation of a strongly bound charge-magnon liquid.

Significant energy corrections from magnon interactions.

Abstract

Understanding mechanisms of quantum ordering in strongly correlated systems remains a central challenge in condensed matter physics, with implications for designing novel quantum materials. Here, we investigate kinetic antiferromagnetism on a triangular lattice under an applied magnetic field, where spin-polarons emerge as charge-magnon bound states with mutual attraction. Using large-scale diagrammatic Monte Carlo simulations, we show that this interaction drives high-temperature phase separation into charge- and magnon-rich regions, bordered by polarised Mott insulating voids. Spectral function analysis reveals a substantial energy correction from magnon interactions, indicating that these carrier-rich regions form a strongly bound charge-magnon liquid. These findings shed new light on recent experiments on MoTe2/WSe2 moir\'e bilayers, underscoring kinetic magnetism as a unique pathway for strong inter-carrier attraction and high-temperature quantum ordering, with potential applications in quantum materials.