Reemergent Metal-Insulator Transitions in Manganites Exposed with Spatial Confinement

The metal-insulator transition is characterized as a single peak in the temperature-dependent resistivity measurements; exceptions to this have never been seen in any single crystal material system. We show that by reducing a single crystal manganite thin film to a wire with a width comparable to the mesoscopic phase-separated domains inherent in the material, a second and robust metal-insulator transition peak appears in the resistivity versus temperature measurement. This new observation suggests that spatial confinement is a promising route for the discovery of emergent physical phenomena in complex oxides.