Transition metal oxides exhibiting a metal-to-insulator transition (MIT) as a function of oxygen vacancy concentration are promising for energy-efficient neuromorphic computing. This paper investigates defective cobaltites, unraveling the structural, electronic, and magnetic changes responsible for the MIT when oxygen vacancies are introduced. It challenges the accepted view, demonstrating that cooperative structural distortions, rather than local bonding changes, drive the MIT. A first-principles model predicts the electric bias needed for the transition, showing good agreement with experimental data and offering a paradigm for designing low-energy devices.

Shenli Zhang, Giulia Galli