membranes*

By combining 2D materials such as graphene into layered van der Waals heterostructures, new types of designer materials with unique and emergent properties have been realized [1]. We describe a method for achieving free-standing single-crystal LaAlO₃/SrTiO₃ membranes by etching away a sacrificial SrRuO₃ layer underneath SrTiO₃. LaAlO₃/SrTiO₃ membranes are transferred to a sapphire substrate, and we use conductive AFM lithography [2] to achieve nanoscale control the insulator to metal transition at the LaAlO₃/SrTiO₃ interface. Nanoscale conductive channels created at room temperature remain conductive at two Kelvin. These results demonstrate the capacity to create LaAlO₃/SrTiO₃ membranes that can be integrated with other materials and reversibly patterned at nanoscale dimensions.

[1] A. K. Geim & I. V. Grigorieva, Nature 499, 419 (2013).

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