Tunable and reconfigurable 2D devices on LaAlO₃/SrTiO₃

The ability to create artificial analogues of various lattice models and engineer metamaterials with a specific topology enables new investigations of emergent properties like superconductivity, magnetism, and correlated electron states. Ultra-Low-Voltage Electron Beam Lithography (ULV-EBL) is one such technique to engineer 2D devices with any arbitrary geometry motivated by theory. It can be used to create reconfigurable conductive nanostructures at the interface of LaAlO₃/SrTiO₃[1]. It was previously employed to create arrays of 1D channels with tunable coupling. ULV-EBL was also shown to be able to write structures through a few layers of materials and was exploited to create a periodic potential beneath graphene. In addition to creating clean 2D devices, it is equally important to be able to tune their chemical potential in order to access quantized ballistic states and get information about the band structure. Here, we create 2D structures and characterize their transport properties at different temperatures and magnetic fields. We explore different options for gating, such as a global metal back gate, virtual side gate at LAO/STO interface through ULV-EBL, and a top gate using graphite/hBN, and discuss their merits and drawbacks. We also attempt to tackle some issues like rewritability and protecting devices from decay, enhancing this platform for quantum simulations and band structure engineering.