Reconfigurable edge-state engineering in graphene using LaAlO3/SrTiO3 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 LaAlO3/SrTiO3 (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 [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 LAO/STO nanostructures shift the position of graphene CNP by ∼1012 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/e2 and h/3e2 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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 25, 2019
- Source ID
- 10.1063/1.5080251
Entities
People
- Brian D'Urso
- Chang-Beom Eom
- Hyungwoo Lee
- Jen-Feng Hsu
- Jeremy Levy
- Jianan Li
- Jung-Woo Lee
- Lu Chen
- Patrick Irvin
- Qing Guo
- Shan Hao
- Yang Hu
Organizations
- Air Force Office of Scientific Research
- Montana State University
- National Science Foundation
- Office of Naval Research
- Pittsburgh Quantum Institute
- University of Pittsburgh
- University of Wisconsin–Madison