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Thursday seminars - Ab initio study of magnetic skyrmions in 2D materials : from fundamentals to device applications

Thursday, September 15 2022, 11.00 am, CEMES (coffee served at 10.30 am), + Zoom

by Dongzhe Li
CNRS researcher at CEMES

Zoom link :

Magnetic skyrmions – topologically protected chiral spin structures with particle-like properties – show great promise for spintronic applications. The Dzyaloshinskii-Moriya interaction (DMI) is often recognized as the key ingredient in forming such localized noncollinear magnetic structures.

The recent discovery of truly 2D magnetic materials opened up new opportunities for exploring magnetic skyrmions in atomically thin vdW materials.

In this talk, using ab initio theory, we predict the emergence of a large DMI in Fe3GeTe2 vdW heterostructures. In particular, the DMI turns out to be highly tunable by strain and electric field, leading to a giant DMI comparable to that of ferromagnetic/heavy metal interfaces, which have been recognized as prototype systems to host skyrmions.

Then, our atomistic spin simulations show that the efficient control of the DMI, the exchange coupling, and the magnetic anisotropy energy by strain lead to stabilizing zero-field skyrmions with diameters close to 10 nm, becoming technologically competitive.

Finally, we theoretically propose vertical tunnel junctions for skyrmion racetrack memories based on 2D magnets, which do not rely on an external magnetic field for device operations. Using non-equilibrium Green’s function formalism, we furthur demonstrate that the proposed tunnel junctions can realize a reliable all-electrical detection scheme for skyrmions.