Dual Control of Giant Field-like Spin Torque in Spin Filter Tunnel Junctions
We predict a giant field-like spin torque, T⊥, in spin-filter (SF) barrier tunnel junctions in sharp contrast to existing junctions based on nonmagnetic passive barriers. We demonstrate that T⊥ has linear bias behavior, is independent of the SF thickness, and has odd parity with respect to the SF’s exchange splitting. Thus, it can be selectively controlled via external bias or external magnetic field which gives rise to sign reversal of T⊥ via magnetic field switching. (閱讀全文…)
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Spin Transfer Properties of Amine-Ended Single-Molecule Magnetic Junction
We proposed the superior spin injection in amine-ended single-molecule magnetic junction (SMMJ) under stretching process, resulting from the strong hard-hard spinterfacial coupling between Co nanowire and amine linker. Furthermore, we predict anomalous magnetoresistance (MR) effect, including strain-induced sign reversal and bias-induced enhancement of MR value in amine-ended SMMJ with Co tip-like nanowire, which is in sharp contrast to normal MR effect in conventional magnetic tunnel junctions. (閱讀全文…)
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Manipulation of Giant Field-Like Spin Torque in Amine-Ended Single-Molecule Magnetic Junctions
We propose a comprehensive theoretical investigation for the angular, external bias and mechanical strain dependence of the giant field-like spin torque (FLST) effect for amine-ended Co/BDA/Co single-molecule magnetic junctions in the non-collinear magnetic configuration, by employing our newly developed nonequilibrium Green’s function method within the framework of density functional theory. (閱讀全文…)
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Hard-hard coupling assisted anomalous magnetoresistance effect in amine-ended single-molecule magnetic junction
We proposed a single-molecule magnetic junction (SMMJ), composed of a dissociated amine-ended benzene sandwiched between two Co tip-like nanowires. To better simulate the break junction technique for real SMMJs, the first-principles calculation associated with the hard-hard coupling between a amine-linker and Co tip-atom is carried out for SMMJs with mechanical strain and under an external bias. (閱讀全文…)
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Analytic expression for the giant fieldlike spin torque in spin-filter magnetic tunnel junctions
We propose analytic expressions for fieldlike, T⊥, and spin-transfer, T, spin torque components in the spin-filter-based magnetic tunnel junction (SFMTJ), by using the single-band tight-binding model with the nonequilibrium Keldysh formalism. In consideration of multireflection processes between noncollinear magnetization of the spin-filter (SF) barrier and the ferromagnetic (FM) electrode, the central spin-selective SF barrier plays an active role in the striking discovery T⊥ T, which can be further identified by the unusual barrier thickness dependence of giant T⊥. (閱讀全文…)
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