Oscillations of Induced Magnetization in Superconductor-Ferromagnet Heterostructures

Abstract

We study a change in the spin magnetization of a superconductor-ferromagnet (SF) heterostructure, when temperature is lowered below the superconducting transition temperature. It is assumed that the SF interface is smooth on the atomic scale and the mean free path is not too short. Solving the Eilenberger equation we show that the spin magnetic moment induced in the superconductor is an oscillating sign-changing function of the product $hd$ of the exchange field $h$ and the thickness $d$ of the ferromagnet. Therefore the total spin magnetic moment of the system in the superconducting state can be not only smaller (screening) but also greater (anti-screening) than that in the normal state, in contrast with the case of highly disordered (diffusive) systems, where only screening is possible. This surprising effect is due to peculiar periodic properties of localized Andreev states in the system. It is most pronounced in systems with ideal ballistic transport (no bulk disorder in the samples, smooth ideally transparent interface), however these ideal conditions are not crucial for the very existence of the effect. We show that oscillations exist (although suppressed) even for arbitrary low interface transparency and in the presence of bulk disorder, provided that $h\tau \gg 1$ ($\tau$ -- mean free path). At low interface transparency we solve the problem for arbitrary strength of disorder and obtain oscillating magnetization in ballistic regime ($h\tau \gg 1$) and nonoscillating magnetization in diffusive one ($h\tau \ll 1$) as limiting cases of one formula.

10 pages, 2 figures, accepted for publication in Phys. Rev. B

References in corpus (2)

• Half-integer Shapiro steps at the 0-pi crossover of a ferromagnetic Josephson junction
• Long-range odd triplet superconductivity in SF structures with Neel walls

Cited by in corpus (12)

• Inverse proximity effect in superconductor-ferromagnet bilayer structures
• Theory of superconducting and magnetic proximity effect in S$\mid$F structures with inhomogeneous magnetization textures and spin-active interfaces
• Experimental Observation of the Inverse Proximity Effect in Superconductor/Ferromagnet Layered Structures
• Spin polarization and orbital effects in superconductor-ferromagnet structures
• Proximity Effects in Conical-Ferromagnet/Superconductor bilayers
• Thermoelectric Effect in Altermagnet-Superconductor Junctions
• Penetration of Andreev bound states into the ferromagnet in a SrRuO${}_3$/(110)YBa${}_2$Cu${}_3$O${}_{7-\delta }$ bilayer: a scanning tunneling spectroscopy study
• Nanoscale spin ordering and spin screening effects in tunnel ferromagnetic Josephson junctions
• Magnetic impurities in a superconductor: Effect of domain walls and interference
• Reentrant proximity-induced superconductivity for GeTe semimetal
• Giant electromagnetic proximity effect in superconductor/ferromagnet superlattices
• Proximity Induced Non-collinear Magnetic States in Planar Superconductor/Ferromagnet Hybrids