Triplet superconductivity in superconductor-ferromagnet hybrids: simulations &amp; experiment

In superconductor-ferromagnet hybrids the opposite-spin singlet Cooper-pairs are transformed to equal-spin triplet correlations. A magnetic non-collinearity at the SF interface is essential for this conversion. This can be achieved in systems where two ferromagnets have a misaligned magnetization with respect to each other. The optimal system for triplet generation is then investigated with the help of micromagnetic simulations. Out of the various systems studied, a disk geometry consisting of nickel and cobalt layers proved to be the most promising. This system was fabricated and subsequently measured. Although the existence of triplet correlations are yet to be verified, a fully proximized junction was observed. In addition, an attempt is made to realise current induced magnetization switching by utilising 100% spin-polarized current from half-metallic CrO2. We expect the required current density to be significantly reduced, thus minimizing the energy dissipation, which is...Show moreIn superconductor-ferromagnet hybrids the opposite-spin singlet Cooper-pairs are transformed to equal-spin triplet correlations. A magnetic non-collinearity at the SF interface is essential for this conversion. This can be achieved in systems where two ferromagnets have a misaligned magnetization with respect to each other. The optimal system for triplet generation is then investigated with the help of micromagnetic simulations. Out of the various systems studied, a disk geometry consisting of nickel and cobalt layers proved to be the most promising. This system was fabricated and subsequently measured. Although the existence of triplet correlations are yet to be verified, a fully proximized junction was observed. In addition, an attempt is made to realise current induced magnetization switching by utilising 100% spin-polarized current from half-metallic CrO2. We expect the required current density to be significantly reduced, thus minimizing the energy dissipation, which is currently the greatest obstacle in fabricating fully functional spintronic devices.Show less

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Triplet superconductivity in superconductor-ferromagnet hybrids: simulations & experiment