Reconfigurable Edge-State Engineering in Graphene Using LaAlO3/SrTiO3 Nanostructures
Journal Article - Open Access
University of Pittsburgh Pittsburgh United States
Pagination or Media Count:
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 LaAlO3SrTiO3 LAOSTO heterostructures and conductive atomic force microscope c-AFM lithography. The local electron density and resulting conductivity of the LAOSTO interface can be patterned with a conductive AFM tip Cen et al., Nat. Mater. 7, 298 2008 and placed within two nanometers of an active graphene device Huang et al., APL Mater. 3, 062502 2015. The proximal LAOSTO nanostructures shift the position of graphene CNP by tilde10exp 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 he2 and h3e2 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.
- Industrial Chemistry and Chemical Processing
- Inorganic Chemistry
- Physical Chemistry