First-principles analysis of a Dzyaloshinskii-Moriya driven magnetic structure in a monolayer Cr on W(110)

The observation of a chiral magnetic spin spiral in a magnetic Mn monolayer on a W(110) substrate has opened a new vista in low-dimensional magnetism [1] with possible applications in spintronics. The origin was explained by the occurrence of the Dzyaloshinskii-Moriya interaction (DMI), which occurs due to the presence of a structure inversion-asymmetry. In this talk, we turn our attention to a monolayer Cr on W(110) [2]. We show by DFT calculations, that the DMI is so strong that it creates a non-collinear spin-spiral ground state, with excellent agreement to spin-polarized STM experiments [3]. We determine a considerable inhomogeneity of the spin spiral by means of a micromagnetic model. We compare our results to the systems Mn and Fe on W(110), where the direction of the spiral and period length are different. We present a minimal tight binding model [4] and show that indeed the sign and strength of the DMI reveals a non-trivial dependence on the electronic structure. \\[4pt] [1] M. Bode \textit{et al.}, Nature \textbf{447}, 190 (2007).\\[0pt] [2] B. Zimmermann \textit{et al.}, Phys. Rev. B \textbf{90}, 115427 (2014).\\[0pt] [3] B. Santos \textit{et al.}, New J. Phys. \textbf{10}, 013005 (2008).\\[0pt] [4] V. Kashid \textit{et al.}, Phys. Rev. B \textbf{90}, 054412 (2014).