Topological transverse spin, charge and heat transport driven by temperature gradients in transition-metal compounds from first principles

点击翻译按钮获取中文摘要

In the field of spintronics, it became clear that new ways of generating and detecting spinpolarized charge as well as pure spin currents have to be introduced and developed. There is a vision that new advances are possible within the new paradigm of utilizing charge and spin currents generated by thermal gradients in various materials. At the current level of development of this promising and completely unexplored field, tagged as spin caloritronics, any insights or even basic level of understanding from the point of view of properties of real materials, which can be successfully described within the density functional theory, are extremely valuable. The purpose of this project is qualitative understanding and quantitative prediction of transverse spin, charge and heat transport properties of metallic ferromagnets and paramagnets stemming from applied thermal gradients. We aim at extending and applying the first principles methodology for computing the charge and spin conductivities within the setup of spin (SHE) and anomalous Hall effects (AHE), developed over the past years in our group, to studies of thermal analogs of these phenomena. The latter include well-known experimentally, yet basically not considered theoretically anomalous Nernst effect (ANE), as well as recently suggested spin Nernst effects (SNE) and recently discovered magnon Hall effect (MHE). While a particular focus falls on the appearance and crystalline anisotropy of these phenomena in three-dimensional metals, as well as their physics at surfaces of various type, stemming from the non-trivial topological Berry phases of Bloch electrons in solids with intrinsic spin-orbit interaction, we make a particular point on challenging task of establishing and applying of the first-principles methodology for studies of transverse thermal transport properties of non-collinear magnets with non-trivial exchange and Dzyaloshinksii-Moriya interactions, known to provide a finite contribution to the AHE, SHE and MHE.