2025/08/28 by Deng, Wenzhe, Tai Kai Ng, Ng, Tai Kai
Physics and Astronomy · #Advanced Condensed Matter Physics #Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Statistical Mechanics (cond-mat.stat-mech) #Theoretical and Computational Physics
paper · pdf · doi:10.48550/arxiv.2508.20724
openalex publication_date 2025/08/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
This paper investigates the effect of disorder on a ferromagnetic metal with repulsive interactions. We assume that, in the clean limit, the ferromagnetic state can be described by Stoner mean-field theory and study how disorder affects the the system by using a combined replica + Stoner mean-field approach. At zero temperature, we find that a replica-symmetric ferromagnetic mean-field solution exists in the presence of disorder with a modified Stoner criteria where the ferromagnetism is enhanced by disorder. At finite temperature, a Landau theory is employed to construct the phase diagram, revealing that beyond a critical disorder strength, a spin-glass phase may exist between the high-temperature paramagnetic phase and the low-temperature ferromagnetic phase. For weak (repulsive) interaction where the system is non-ferromagnetic in the clean limit, the possibility of a disordered-induced ferromagnetic ground state is observed both at zero temperature and finite temperature. The potential applicability of this framework to realistic materials is briefly discussed.