Evolution of 0.7 conductance anomaly in electric field driven ferromagnetic CuO junction based resistive random access memory devices

摘要

This study demonstrates the origin of 0.7 conductance anomaly and non-volatile reversible control of switching in atomically controlled resistive random access memory devices. In quantum devices, 0.7 structure and zero bias anomaly (ZBA) are considered as the natural presence of spin state. Here, we show that similar behavior can be detected in an atomically thin electrically controllable break junction based on Cu/Ti/HfO2/TiN resistive switches in which the origin of the 0.7 structure is statistically controlled by the device design, filament geometry, and optimized electrical measurement scheme. Evidence of temperature dependent evolution of 0.7 plateau and low temperature ZBA is presented here. Lorentzians of the experimental result indicate the formation of a ZBA and non-ZBA like state at a low resistance state and a high resistance state of the resistive switches. Repeated spin-like switching is achieved by controlling the chemical composition of the filament in the sub-quantum region by the electric field driven ion redistribution process. During switching, formation of a ferromagnetic CuO atom in the break junction surrounded by Cu electron sources, i.e., nanoionics, manifests the suitable environment for spin-like behavior.