Jahn–Teller Effect Induces Exchange Bias in Ultrasmall Magnetite

(3d5) spins via double exchange, bypassing conventional interfacial interactions. This work establishes Jahn-Teller driven symmetry breaking as a new mechanism for exchange bias in quantum-confined systems, opening pathways for engineering emergent spin correlations in single-phase 0D spintronic architectures with three-dimensional nanoconfinement (nm × nm × nm scale).