Memristor-like behavior and negative resistance in a superconductor/insulator/ferromagnet device with a pinholes-governed interface

We investigate the voltage–current characteristics of a superconductor–insulator–ferromagnet heterostructure, where the insulating layer contains pinhole-defects. The superconducting layer exhibits multiple voltage jumps that are hysteretic with the current sweep direction. This characteristic of the resistive state is due to pinholes that induce local, distinct, coupling regions between the superconducting and ferromagnetic layers which may generate phase-slip lines or vortex channeling. These findings point to a magnetically driven design of a superconductor memristor. Concomitantly, the junctions display both absolute and differential negative resistances below the superconducting critical temperature and current. This anomalous behavior is analyzed using a circuit approach and is attributed to current passing through pinholes within the insulating layer. These two unique effects, which stem from the special topology of the pinholes-governed interface can be applied in superconductor-based switches and memory devices.