Nano-patterning of the electron gas at the LaAlO3/SrTiO3 interface using low-energy ion beam irradiation

Abstract

The quasi-two dimensional electron gas formed at the interface between LaAlO3 (LAO) and SrTiO3 (STO) shows fascinating properties, such as two-dimensional superconductivity, giant electric field effect, and the possible co-existence of ferromagnetic and superconducting phases. In this work, we demonstrate that the conducting LAO/STO interface can be made insulating after short irradiation by a beam of low energy Ar+ ions. The irradiation process does neither result in physical removal of the LAO film nor produces oxygen vacancies in the STO layer. Using electron beam lithography and low ion beam energy irradiation, we fabricated conducting nano-structures in the LAO/STO interface with dimensions down to 50 nm. Such a reliable and robust method of nano-patterning may be a prerequisite for future electronic applications of the LAO/STO interface.