We report measurements of the superconducting transition temperature, T c , in CoO/Co/Cu/Co/Nb multilayers as a function of the angle α between the magnetic moments of the Co layers. Our measurements reveal that T c (α) is a nonmonotonic function, with a minimum near α = π/2. Numerical self-consistent solutions of the Bogoliubov-de Gennes equations quantitatively and accurately describe the behavior of T c as a function of α and layer thicknesses in these superconductor / spin-valve heterostructures. We show that experimental data and theoretical evidence agree in relating T c (α) to enhanced penetration of the triplet component of the condensate into the Co/Cu/Co spin valve in the maximally noncollinear magnetic configuration.

Energy loss due to ohmic heating is a major bottleneck limiting down-scaling and speed of nano-electronic devices, and harvesting ohmic heat for signal processing is a major challenge in modern electronics. Here, we demonstrate that thermal gradients arising from ohmic heating can be utilized for excitation of coherent auto-oscillations of magnetization and for generation of tunable microwave signals. The heat-driven dynamics is observed in Y3Fe5O12/Pt bilayer nanowires where ohmic heating of the Pt layer results in injection of pure spin current into the Y3Fe5O12 layer. This leads to excitation of auto-oscillations of the Y3Fe5O12 magnetization and generation of coherent microwave radiation. Our work paves the way towards spin caloritronic devices for microwave and magnonic applications.

Nonlinear magnon scattering redefines how nanomagnets respond to spin currents.

Dislocations in a material will, when present in enough numbers, change the speed of propagation of elastic waves. Consequently, two material samples, differing only in dislocation density, will have different elastic constants, a quantity that can be measured using Resonant Ultrasound Spectroscopy. Measurements of this effect on aluminum samples are reported. They compare well with the predictions of the theory.

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