Strain-promoted reversible spin transfer in rhombic graphene nanoflakes

[Display omitted] •Tensile strain can significantly promote the spin-dynamics processes on GNFs.•Spin-transfer processes can be triggered by the applied tensile strain.•Reversible spin flip and spin transfer can be realized simultaneously with strain.•Coupling effects of strain, laser pulses, and magnetic fields on GNFs is presented. The strain-promoted reversible spin flip and spin transfer on double-magnetic-center graphene nanoflakes (Ni2&GNFs) are investigated with first-principles quantum chemical computations. We find that applying strain along the two diagonals of the rhombic graphene nanoflakes can significantly lead to the redistribution of spin density, and can therefore dominate the spin-flip and spin-transfer processes. The applied strain effectively changes the spin-density localization of the system, thus opening a channel for successful spin-transfer processes in all distorted structures. Especially, simultaneous spin-flip and transfer processes are achieved when the tensile strain is applied along the short diagonal, and some of the spin-transfer and spin-flip-transfer scenarios achieved on the stretched Ni2&GNF are reversible. This reversible strain-assisted spin dynamics provides a feasible yet efficient way to control the spin magnetism of GNFs, which could increase the functionality and the flexibility of the integrated spin-logic in real straintronic devices.