Reconfigurable 2D electron gases in topologically strained domain walls
Domain walls (DWs) in ferroelectric wide band-gap materials constitute novel topological entities that may be rendered fully conductive under certain circumstances. Domain walls separate areas of different polarization and show an ultra-small width of approximately 1-2 nm only, but extend fully across the single crystal under investigation. Hence, a 2-dimensional electron gas (2DEG) is confined within such a tiny wall. For the last 5 years, efforts have been undertaken to maximize that electron current in the DW, through chemical and topological DW tuning, reaching values of up to several µA flowing along the DW under a 10 V bias. In this project these novel topologies will be explored towards applications in quantum hall devices at room temperature. Since DWs can be written and erased practically on will, the approach sketched here allows reconfiguring such a quantum device in-situ. Moreover, the domain wall current may be further increased through mechanically straining the host material that supports the 2DEG.
Your work will be supervised by two institutions, the Institute of Applied Physics (IAP) at TU Dresden and the Max-Planck Institute for Chemical Physics of Solids (CPfS) in Dresden, Germany. Exploring the full spectrum of novelty in this fascinating new topic will bring you also in contact with collaborators working on complementary techniques such as angle-resolved photoemission or synchrotron light sources in Europe.