Magnetic fluctuations driven by quantum geometry
This work decomposes magnetic fluctuations in LaFeAsO and Pb9Cu(PO4)6O into two parts: one from band dispersion and one from quantum geometry. The results show that the geometric contribution dominates, driving antiferromagnetic fluctuations in LaFeAsO and stabilizing ferromagnetic fluctuations in Pb9Cu(PO4)6O. This demonstrates that quantum geometry is essential for understanding magnetic behavior in multi-band systems.