  Recent reports of superconductivity at KTaO3 (KTO) (110) and (111) interfaces
have sparked intense interest due to the relatively high critical temperature
as well as other properties that distinguish this system from the more
extensively studied SrTiO3 (STO)-based heterostructures. Here we report
nanoscale control of the metal-to-insulator transition at the LaAlO3/KTO (110)
and (111) interfaces. Devices are created using two distinct methods previously
developed for STO-based heterostructures: (1) conductive atomic-force
microscopy lithography and (2) ultra-low-voltage electron-beam lithography. At
low temperatures, KTO-based devices show superconductivity that is tunable by
an applied back gate. A nanowire device shows single-electron-transistor (SET)
behavior. These reconfigurable methods of creating nanoscale devices in
KTO-based heterostructures offer new avenues for investigating mechanisms of
superconductivity as well as development of quantum devices that incorporate
strong spin-orbit interactions, superconducting behavior, and nanoscale
dimensions.
