Resonant Tunneling Current in an Atomically Designed SrRuO₃/SrTiO₃ Superlattices

Superlattices which has a Superlattices that have a strong correlation with each layer have been studied a lot in both electrical and optical applications since the first observation of negative differential resistance [NDR] due to its intrigue band structure. Expecially NDR in low-dimensional materials has been attracted for ultra-low power consuption, simple circuit, and multi-logic application. But still, it is hard to apply to the real application due to the breakdown problem hysteresis behavior, and unipolar propertiy. In this, we designed SrRuO₃/SrTiO₃ oxide superlattice which shows the differrent tunneling current depend on SrTiO₃ thickness. The resonant tunneling occured the resonant state of SrRuO₃, and NDR was generated in both top and bottom edge states, which showed bipolar operation. And as SrTiO₃ thickness increased, two resonant peaks appeared coming from the dielectric dead layer at SrRuO₃/SrTiO₃ inferfaces with large hysteresis. The systematical analysis of NDR in superlattices can be a key for the future application.