Ramp-Reversal Memory and Phase-Boundary Scarring in Transition Metal Oxides.

Transition metal oxides are complex electronic systems that exhibit a multitude of collective phenomena. Two archetypal examples are VO and NdNiO , which undergo a metal-insulator phase transition (MIT), the origin of which is still under debate. Here this study reports the discovery of a memory effect in both systems, manifested through an increase of resistance at a specific temperature, which is set by reversing the temperature ramp from heating to cooling during the MIT.