High spin mixing conductance and spin interface transparency at the interface of a Co2Fe0.4Mn0.6Si Heusler alloy and Pt

Ferromagnetic materials exhibiting low magnetic damping (α) and moderately high-saturation magnetization are required from the viewpoints of generation, transmission, and detection of spin waves. Since spin-to-charge conversion efficiency is another important parameter, high spin mixing conductance $$({g_{r}^{\uparrow \downarrow}})$$ ( g r ↑ ↓ ) is the key for efficient spin-to-charge conversion. Full Heusler alloys, e.g., Co2Fe0.4Mn0.6Si (CFMS), which are predicted to be 100% spin-polarized, exhibit low α. However, $$g_r^{ \uparrow \downarrow }$$ g r ↑ ↓ at the interface between CFMS and a paramagnet is not fully understood. Here, we report investigations of spin pumping and the inverse spin Hall effect in CFMS/Pt bilayers. Damping analysis indicates the presence of significant spin pumping at the interface of CFMS and Pt, which is also confirmed by the detection of an inverse spin Hall voltage. We show that in CFMS/Pt, $$g_r^{ \uparrow \downarrow }$$ g r ↑ ↓ (1.70 × 1020 m−2) and the interface transparency (83%) are higher than the values reported for other ferromagnetic/heavy metal systems. We observed a spin Hall angle of ~0.026 for the CFMS/Pt bilayer system.

Selective interface transparency in graphene nanoribbon based molecular junctions

We investigate the interface effects in graphene based all-carbon molecular electronics and probe opposite effects with respect to the intrinsic feature of an embedded core graphene nanoflake (GNF). For metallic GNFs, good/poor contact transparency occurs when the core device aligns with the center/edge of the electrode. The situation is reversed for a semiconducting GNF as a device.

Role of Interface Transparency and Exchange Field in the Superconducting Triplet Spin-Valve Effect

We study the superconducting transition temperature Tc of F2/F1/S trilayers (Fi is a metallic ferromagnet, S is a s-superconductor), where the long-range triplet superconducting component is generated at canted magnetizations of the F layers. In this paper we show that it is possible to realize different spin-valve effect modes - the standard switching effect, the triplet spin-valve effect, reentrant Tc(α) dependence or reentrant Tc(α) dependence with the inverse switching effect - by variation of the F2/F1 interface transparency or the exchange splitting energy. In addition, we show that positionof the Tc minimum can be changed by joint variation of the F2/F1 interface transparency and the layerthicknesses.

FCS OF SUPERCONDUCTING TUNNEL JUNCTIONS IN NONEQUILIBRIUM

We analyze the full counting statistics (FCS) of a superconducting junction in nonequilibrium in the limit of small interface transparency. In this limit we treat both supercurrent and multiple Andreev reflections on equal footing and show how to generalize previous results for both phenomena. Furthermore, we also allow for different gaps of both superconductors and investigate the intermediate regime which allows to make contact with previous results on normal-superconductor heterostructures. We also compare our predictions in this regime to experimental data.