Driven spin transitions in fluorinated single- and bilayer-graphene quantum dots. (22nd May 2017)

• Record Type: Journal Article
• Authors: Żebrowski, D P; Peeters, F M; Szafran, B
• Is Part Of: Semiconductor science and technology. Volume 32:Number 6(2017:Jun.)
• Publication Date: 2017-05-22
• Subjects: tight-binding modeling -- electric-dipole-spin resonance -- bilayer graphene -- electric dipole spin resonance; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1361-6641/aa6df4
• Languages: English
• ISSNs: 0268-1242

Abstract

Abstract: Spin transitions driven by a periodically varying electric potential in dilute fluorinated graphene quantum dots are investigated. Flakes of monolayer graphene as well as electrostatic electron traps induced in bilayer graphene are considered. The stationary states obtained within the tight-binding approach are used as the basis for description of the system dynamics. The dilute fluorination of the top layer lifts the valley degeneracy of the confined states and attenuates the orbital magnetic dipole moments due to current circulation within the flake. The spin–orbit coupling introduced by the surface deformation of the top layer induced by the adatoms allows the spin flips to be driven by the AC electric field. For the bilayer quantum dots the spin flip times is substantially shorter than the spin relaxation. Dynamical effects including many-photon and multilevel transitions are also discussed.