Crossroad quantum dots in Graphene

In this study, we present the fabrication and characterization of quantum dots (QDs) based on a cross-road structure where geometric confinement and the specific cross-road architecture are expected to lead to two discrete electronic states separated from a continuum [1,2]. These QD devices are fabricated from few-layer graphene films with the help of e-beam lithography technique aiming at widths of the individual graphene ribbons of about 80 nm. The resulting structures exhibit novel properties that we investigate through electric transport measurements, allowing us to probe the energy levels within these devices. The combination of graphene's high carrier mobility with the geometrically tunable level spacing of the QDs offers a promising platform for diverse quantum device application. This research advances our understanding of low-dimensional QD systems and paves the way for the development of next-generation quantum technologies.

 

Financial support by the National Science Foundation through EPSCoR RII Track-1: Emergent Quantum Materials and Technologies (EQUATE), Award OIA-2044049 is acknowledged. The research was performed in part in the Nebraska Nanoscale Facility: National Nanotechnology Coordinated Infrastructure and the Nebraska Center for Materials and Nanoscience, which are supported by NSF under Award ECCS: 2025298, and the Nebraska Research Initiative.

 

[1] R. L. Schult, D. G. Ravenhall, and H. W. Wyld Phys. Rev. B 39, 5476(R) (1989)

[2] A F Sadreev 2021 Rep. Prog. Phys. 84 055901 DOI 10.1088/1361-6633/abefb9