Reconfigurable edge-state engineering in graphene using LaAlO${}_3$/SrTiO${}_3$ nanostructures

Abstract

The properties of graphene depend sensitively on doping with respect to the charge-neutrality point (CNP). Tuning the CNP usually requires electrical gating or chemical doping. Here, we describe a technique to reversibly control the CNP in graphene with nanoscale precision, utilizing LaAlO${}_3$/SrTiO${}_3$ (LAO/STO) heterostructures and conductive atomic force microscope (c-AFM) lithography. The local electron density and resulting conductivity of the LAO/STO interface can be patterned with a conductive AFM tip, and placed within two nanometers of an active graphene device. The proximal LAO/STO nanostructures shift the position of graphene CNP by ~ $10^{12}$ cm${}^{-2}$, and are also gateable. Here we use this effect to create reconfigurable edge states in graphene, which are probed using the quantum Hall effect. Quantized resistance plateaus at $h/e^2$ and $h/3e^2$ are observed in a split Hall device, demonstrating edge transport along the c-AFM written edge that depends on the polarity of both the magnetic field and direction of currents. This technique can be readily extended to other device geometries.

arXiv comment12 pages

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Cited by in corpus (4)

• Nanoscale control of LaAlO3/SrTiO3 metal-insulator transition using ultra-low-voltage electron-beam lithography
• Gate-Tunable Optical Nonlinearities and Extinction in Graphene/LaAlO${}_3$/SrTiO${}_3$ Nanostructures
• Nanoscale ferroelectric programming of van der Waals heterostructures
• Gate-Tunable Optical Extinction of Graphene Nanoribbon Nanoclusters