Geometrical dependence of spin current absorption into a ferromagnetic nanodot

Abstract

We have investigated the absorption property of the diffusive pure spin current due to a ferromagnetic nanodot in a laterally configured ferromagnetic/nonmagnetic hybrid nanostructure. The spin absorption in a nano-pillar-based lateral-spin-valve structure was confirmed to increase with increasing the lateral dimension of the ferromagnetic dot. However, the absorption efficiency was smaller than that in a conventional lateral spin valve based on nanowire junctions because the large effective cross section of the two dimensional nonmagnetic film reduces the spin absorption selectivity. We also found that the absorption efficiency of the spin current is significantly enhanced by using a thick ferromagnetic nanodot. This can be understood by taking into account the spin absorption through the side surface of the ferromagnetic dot quantitatively.

Enhanced spin accumulation in nano-pillar-based lateral spin valve using spin reservoir effect

“…Such an influence of the spin accumulation properties by spin injector materials, geometry structures and boundary conditions could be recognized as a spin reservoir effect. To improve the spin accumulation properties with respect to the spin reservoir effect, one of the best candidate structures is pillar-based lateral spin valves (pLSVs), where the ferromagnetic electrodes are nano-sized dots [31][32][33][34]. Compared to the wire-based lateral spin valves (wLSVs), the Joule heating effect can be significantly reduced owing to the strong heat sink in the spin channel.…”

Magnetic field manipulation of spin current in a single-molecule magnet tunnel junction with two-electron Coulomb interaction

“…54 It is shown that an efficient pure-spin-current injection can be used to realize the magnetization switching of a nano-scale ferromagnetic particle and measurements of room temperature spin Hall effect as well. 36,55,56 The thermoelectric transport through quantum dots [57][58][59][60] and magnetic molecules [61][62][63][64] can generate pure spin current in electrodes. It is demonstrated that the device supporting a spin current is also possible to be adopted as an energy harvester.…”

Spin Absorption Effect at Ferromagnet/Ge Schottky-Tunnel Contacts

“…On the other hand, for the spin injection into nonmagnetic metals (NMs), the size of FM/NM junctions was frequently important because of the spin absorption effect at the FM/NM interface [ 32 , 33 , 34 ]. In general, the spin resistance of FM is defined as 2 /[ S (1 − )] [ 30 , 32 ], where S is the effective cross-sectional area, is the spin polarization, and and are the spin diffusion length and resistivity, respectively.…”

“…In general, the spin resistance of FM is defined as 2 /[ S (1 − )] [ 30 , 32 ], where S is the effective cross-sectional area, is the spin polarization, and and are the spin diffusion length and resistivity, respectively. Owing to the unique values of , , and in FM, reducing the size of S enables the increase in the spin resistance of FM, resulting in the suppression of the back flows of spins from NM towards FM [ 32 , 33 , 34 ]. Yang et al demonstrated the generation of a giant pure spin current, leading to the magnetization switching of the nanomagnet by reducing the FM/NM junction size [ 33 ].…”