Nanoscale control of the metal-insulator transition in LAO/KTO heterostructures*

Recent reports of superconductivity at the KTaO₃ (KTO) interfaces [1] introduce new challenges and opportunities for understanding of superconductivity at oxide interfaces. Here we report nanoscale control of the metal-to-insulator transition at LAO/KTO (110) and (111) interfaces. Devices are created using two distinct methods: (1) conductive-AFM lithography [2] and (2) Ultra-low-voltage electron beam lithography [3]. At low temperatures, these devices show superconductivity, tunable by electric fields, as well as strong anisotropy along different crystallographic axes. The creation of nanoscale devices offers new paths for the investigation of underlying mechanisms of superconductivity. Our results also demonstrate that this material system may find its applications in quantum devices that incorporate strong spin-orbit interactions, nanoscale dimensions, and superconducting behavior.

[1] Liu C, et al., Science, 371, 716 (2021). 

[2] Cen C, et al, Nature materials 7, 298 (2008).

[3] Yang D, Applied physics letters, 117, 253103 (2020).