Tunnel magnetoresistance in double spin filter junctions

Abstract

We consider a new type of magnetic tunnel junction, which consists of two ferromagnetic tunnel barriers acting as spin filters (SFs), separated by a nonmagnetic metal (NM) layer. Using the transfer matrix method and the free-electron approximation, the dependence of the tunnel magnetoresistance (TMR) on the thickness of the central NM layer, bias voltage and temperature in the double SF junction are studied theoretically. It is shown that the TMR and electron-spin polarization in this structure can reach very large values under suitable conditions. The highest value of the TMR can reach 99%. By an appropriate choice of the thickness of the central NM layer, the degree of spin polarization in this structure will be higher than that of the single SF junctions. These results may be useful in designing future spin-polarized tunnelling devices.

12 pages, 5 PS figures

References in corpus (4)

• Large magnetoresistance using hybrid spin filter devices
• Constraints on leptophobic gauge bosons with polarized neutrons and protons at RHIC
• Spin-polarized tunneling through a thin-film
• Spin-polarized tunneling in ferromagnetic double barrier junctions

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• Spin-dependent resonant tunneling in ZnSe/ZnMnSe heterostructures
• Asymmetric Bias Dependence in Double Spin Filter Tunnel Junctions
• Surface state transport in double-gated and magnetized topological insulators with hexagonal warping effects
• Superconducting double spin valve with extraordinary large tunable magnetoresistance