Strain Induced Modulation of Dzyaloshinskii-Moriya interaction in Pt/Co Bilayer Devices: A Green's Function Approach.*

We use first-principles calculations to study the strain induced control of Dzyaloshinskii-Moriya Interaction (DMI) in ultrathin Pt/Co films. We introduce a Greens function approach to calculate the DMI coefficients that compared to the super-cell and Generalized Bloch approaches is computationally more efficient and accurate. We investigate the dependence of the DMI coefficient for Pt/Co[111] bilayer device on the Pt and Co thicknesses. We compare the calculated results versus Co thickness with the reported experimental data, where we observe a relative agreement. Furthermore, we study the effects of normal and shear strains on the DMI tensor elements. We show that normal(shear) strain results in anisotropic Neel- (Bloch-)type DMI.