Modeling of high and low resistant states in single defect atomristors

Resistance-change random access memory (RRAM) devicesare nanoscale metal-insulator-metal structures that can store informationin their resistance states, namely the high resistance (HRS) and lowresistance (LRS) states. They are a potential candidate for a universalmemory as these non-volatile memory elements can offer fast-switching,long retention and switching cycles, and additionally, are also suitablefor direct applications in neuromorphic computing. In this study, we firstpresent a model to analyze different resistance states of RRAM devices orso-called "atomristors" that utilize novel 2D materials as the switchingmaterials instead of insulators. The developed model is then used tostudy the electrical characteristics of a single defect monolayer MoS2memristor. The change in the device resistance between the HRS andLRS is associated to the change in the tunneling probability when thevacancy defects in the 2D material are substituted by the metal atomsfrom the electrodes. The distortion due to defects and substituted metalatom is captured in the 1D potential energy profile by averaging theeffect along the transverse direction. This simplification enables us tomodel single defect memristors with a less extensive quantum transportmodel while taking into account the presence of defects