Origin of inverse Rashba-Edelstein effect detected at the Cu/Bi interface using lateral spin valves

The spin transport and spin-to-charge current conversion properties of bismuth are investigated using permalloy/copper/bismuth (Py/Cu/Bi) lateral spin valve structures. The spin current is strongly absorbed at the surface of Bi, leading to ultrashort spin-diffusion lengths. A spin-to-charge current conversion is measured, which is attributed to the inverse Rashba-Edelstein effect at the Cu/Bi interface. The spin-current-induced charge current is found to change direction with increasing temperature. A theoretical analysis relates this behavior to the complex spin structure and dispersion of the surface states at the Fermi energy. The understanding of this phenomenon opens novel possibilities to exploit spin-orbit coupling to create, manipulate, and detect spin currents in two-dimensional systems

Muscle thickness and echogenicity measured by ultrasound could detect local sarcopenia and malnutrition in older patients hospitalized for hip fracture

Background: The aim of this work was to assess whether the muscle thickness and echogenicity were associated with dysphagia, malnutrition, sarcopenia, and functional capacity in acute hospital admission for a hip fracture. Methods: Observational study that assessed nutritional status by Global Leadership Initiative on Malnutrition, risk of dysphagia and sarcopenia by European Working Group on Sarcopenia in Older People and Barthel functional index. We measured muscle thickness and echogenicity of masseter, bicipital, and quadriceps rectus femoris (RF) and vastus intermedius (VI) by ultrasound. Results: One hundred and one patients were included in the study (29.7% sarcopenia and 43.8% malnutrition). Logistic regression models adjusted for age, sex, and body mass index showed an inverse association of the masseter thickness with both sarcopenia (OR: 0.56) and malnutrition (OR: 0.38) and quadriceps with sarcopenia (OR: 0.74). In addition, patients at high risk of dysphagia had lower masseter thickness (p: 0.0001) while patients able to self-feeding had thicker biceps (p: 0.002) and individuals with mobility on level surfaces higher thickness of biceps (p: 0.008) and quadriceps (p: 0.04). Conclusion: Thickness of the masseter was associated with risk of dysphagia, biceps with the ability to self-feed, and that of the quadriceps RF-VI with mobility

Ultrathin manganite films grown by pulsed-plasma deposition

Ultrathin ferromagnetic films of La0.7Sr0.3MnO3 were deposited by electron-beam ablation on standard SrTiO3(1 0 0) and NdGaO3(1 1 0) substrates. Even 4 nm films are metallic and develop spontaneous magnetization at room temperature: similar hysteresis cycles were measured by magneto optical Kerr effect (MOKE) in the longitudinal configuaration and by SQUID magnetometry. To the best of our knowledge the 4 nm thickness corresponds so far to the thinnest manganite film showing room-temperature ferromagnetism

Room-temperature spintronic effects in Alq3-based hybrid devices

We report on efficient spin polarized injection and transport in long (102 nm) channels of Alq3 organic semiconductor. We employ vertical spin valve devices with a direct interface between the bottom manganite electrode and Alq3, while the top-electrode geometry consists of an insulating tunnel barrier placed between the “soft” organic semiconductor and the top Co electrode. This solution reduces the ubiquitous problem of the so-called ill-defined layer caused by metal penetration, which extends into the organic layer up to distances of about 50–100 nm and prevents the realization of devices with well-defined geometry. For our devices the thickness is defined with an accuracy of about 2.5 nm, which is near the Alq3 molecular size. We demonstrate efficient spin injection at both interfaces in devices with 100- and 200-nm-thick channels. We solve one of the most controversial problems of organic spintronics: the temperature limitations for spin transport in Alq3-based devices. We clarify this issue by achieving room-temperature spin valve operation through the improvement of spin injection properties of both ferromagnetic/Alq3 interfaces. In addition, we discuss the nature of the inverse sign of the spin valve effect in such devices proposing a mechanism for spin transport