Towards long-range triplets in FSF heterostructures fabricated through shadow evaporation

This paper presents an initial approach to investigate the feasibility of fabricating FSF heterostructures, for potential applications in spintronics. These FSF stacks could help characterize long-range triplet Cooper pairs that are created at its interfaces. Simulations inform the final design of a 3D FSF stack, composed of one low and one high aspect ratio rectangular shape. Subsequent efforts were directed on the focused ion beam milling of apertures in 1 µm thick Si3N4 membranes that are used for shadow evaporation of the heterostructures. Several stacks of cobalt and niobium were fabricated with these membranes through shadow evaporation. These heterostructures were contacted via electron beam lithography and measured in a vectormagnet cryostat. Results indicate that no long-range triplets were generated inside the FSF stacks. It can be concluded that either the niobium layers did not become superconducting or the magnetization of the two ferromagnets in the stacks were not...Show moreThis paper presents an initial approach to investigate the feasibility of fabricating FSF heterostructures, for potential applications in spintronics. These FSF stacks could help characterize long-range triplet Cooper pairs that are created at its interfaces. Simulations inform the final design of a 3D FSF stack, composed of one low and one high aspect ratio rectangular shape. Subsequent efforts were directed on the focused ion beam milling of apertures in 1 µm thick Si3N4 membranes that are used for shadow evaporation of the heterostructures. Several stacks of cobalt and niobium were fabricated with these membranes through shadow evaporation. These heterostructures were contacted via electron beam lithography and measured in a vectormagnet cryostat. Results indicate that no long-range triplets were generated inside the FSF stacks. It can be concluded that either the niobium layers did not become superconducting or the magnetization of the two ferromagnets in the stacks were not perpendicular.Show less

Leiden University Student Repository

Documents

In Collections

Towards long-range triplets in FSF heterostructures fabricated through shadow evaporation