Affiliation
RIKEN CEMS
Title
Superconductivity at epitaxial LaTiO3-KTaO3 interfaces
Abstract
The design of epitaxial interfaces is a pivotal way to engineer artificial structures where new electronic phases can emerge. Here, we report a systematic emergence of an interfacial superconducting state in epitaxial heterostructures of Mott insulator LaTiO$_3$ and band insulator KTaO$_3$ with large spin-orbit coupling. The LaTiO$_3$ layer has a non-trivial impact on the emergence of the superconducting phase. With increasing LaTiO$_3$ thickness, the superconducting transition temperature decreases and a finite resistance remains below the transition. Such a behavior is observed for both (110) and (111) crystal oriented structures. Consistent with previous reports, the (001) oriented heterointerface features a high electron mobility of 250 cm$^2$ V$^{−1}$ s$^{−1}$ and shows no superconducting transition down to 40 mK. Our result may pave the way for engineering superconducting interfaces with non-trivial electronic states and integrating superconducting KTaO$_3$ interfaces with oxide materials.
Reference:
D. Maryenko, I. V. Maznichenko, S. Ostanin, M. Kawamura, K. S. Takahashi,M. Nakamura, V. K. Dugaev, E. Ya. Sherman, A. Ernst, M. Kawasaki, APL Materials 11, 061102 (2023)