Charge order through crystallization of Frenkel excitons: realization in kagome metals
The paper proposes an alternative mechanism for charge order in ionic materials: the crystallization of long-lived Frenkel excitons. This scenario explains charge correlations by balancing potential and kinetic energies during exciton formation, leading to a periodic lattice of these excitons. It offers a microscopic explanation for both local charge correlations and long-range ordering, contrasting with standard Fermi surface instability theories.