Transport Properties in Interacting Graphene Quantum Dots

Chemically derived graphene quantum dots (QD) hold great promise for applications in electronics, optoelectronics, and bioelectronics. Using a gate electrode, it is possible to control the number of electrons contained in the dot as well as the current flow when electrodes are attached. Experimentally, the fabrication of atomically precise graphene QDs consisting of low-bandgap armchair graphene nanoribbon (AGNR) segments were recently reported [1]. In this work, we apply a combination of dynamic mean field theory [2] and a molecular-based non-equilibrium Green's function technique coupled to DFT [3,4] to tackle the problem of interacting electrons in graphene quantum dots in AGNR including a gate electrode. We observe conductance peaks associated with the localized states related to the graphene QDs presented in the AGNR in a realistic parameters range giving us precise gap tunability. Such device can be used to design a graphene-based single electron transistor.
References:
[1] Wang, S. et. al., Nano Lett., v. 17, p. 4277, 2017.
[2] Leonov, I et. al., Physical Review Letters, v. 101, p. 096405, 2008.
[3] Brandbyge, M et. al., Physical Review B, v. 65, p. 165401, 2002.
[4] Rocha, A et. al., Physical Review B, v. 73, p. 085414, 2006.