Various experiments have indicated that electron transfer through nonmagnetic chiral hydrocarbon molecules is spin dependent. This property is called the chiral-induced spin selectivity (CISS)...Show moreVarious experiments have indicated that electron transfer through nonmagnetic chiral hydrocarbon molecules is spin dependent. This property is called the chiral-induced spin selectivity (CISS) effect and its presence cannot be explained with current theoretical models. To detect the CISS effect experimentally, chiral molecules have to be isolated. Therefore, transport through a single chiral molecule must be measured with STM. A fabrication procedure for sharp and stable nickel STM tips has been developed using electrochemical etching. The produced tips are very sharp and have an average opening angle of 18.9° and an apex size below 200 nm. The magnetic polarisation of the tip can be reversed in situ by a magnetic field, induced by a coil around the tip, which has been demonstrated. The quality and the magnetisation of the tips have been tested on HOPG, gold and nickel with STM. Clear large-scale images were obtained on all materials. Atomic resolution was obtained on HOPG. With these challenges resolved, STM measurements using a nickel tip with both magnetic polarisations can be performed in the study of single chiral molecules as spin filter and the investigation of the CISS effect.Show less
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...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
