Colossal Proximity Effect in a Superconducting Triplet Spin Valve Based on the Half-Metallic Ferromagnet<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>CrO</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Singh, Amarjit; Voltan, S.; Lahabi, Kaveh; Aarts, J.

doi:10.1103/physrevx.5.021019

Cited by 149 publications

(180 citation statements)

References 24 publications

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“…Half-metallic (H) ferromagnets (already employed in various superconducting hybrid structures, see, e.g., Refs. [12,13]) should lead to highly efficient splitting due to absolute spin filtering. At the same time, mutual orientation of magnetizations in the two arms can, in principle, be varied continuously by weak external magnetic field if one of the arms is exchange biased (a scheme similar to, e.g., Ref.…”

Section: Introductionmentioning

confidence: 99%

Cooper pair splitting in diffusive magnetic SQUIDs

et al. 2017

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We study Josephson junctions with weak links consisting of two parallel disordered arms with magnetic properties -ferromagnetic, half-metallic or normal with magnetic impurities. In the case of long links, the Josephson effect is dominated by mesoscopic fluctuations. In this regime, the system realises a ϕ0 junction with sample-specific ϕ0 and critical current. Cooper pair splitting between the two arms plays a major role and leads to 2Φ0 periodicity of the current as a function of flux between the arms. We calculate the current and its flux and polarization dependence for the three types of magnetic links.

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Section: Introductionmentioning

confidence: 99%

Cooper pair splitting in diffusive magnetic SQUIDs

et al. 2017

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“…Those groups found evidence for spin-triplet generation occurring during the magnetization reversal process while sweeping an external magnetic field. Better control of the magnetic states has been achieved recently by several groups measuring the critical temperature T c of S/F/F trilayers, where generation of spin-triplet correlations results in lowering of T c [21][22][23][24][25][26]. Controlling T c , however, is less likely to be useful for future device applications than controlling supercurrent.…”

mentioning

confidence: 99%

Amplitude Control of the Spin-Triplet Supercurrent inS/F/SJosephson Junctions

Martinez¹,

Pratt²,

Birge³

2016

Phys. Rev. Lett.

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Josephson junctions made with conventional s-wave superconductors and containing multiple layers of ferromagnetic materials can carry spin-triplet supercurrent in the presence of certain types of magnetic inhomogeneity. In junctions containing three ferromagnetic layers, the triplet supercurrent is predicted to be maximal when the magnetizations of adjacent layers are orthogonal, and zero when the magnetizations of any two adjacent layers are parallel. Here we demonstrate on-off control of the spin-triplet supercurrent in such junctions, achieved by rotating the magnetization direction of one of the three layers by 90 • . We obtain "on-off" ratios of 5, 7, and 19 for the supercurrent in the three samples studied so far. These observations directly confirm one of the most salient predictions of the theory, and pave the way for applications of spin-triplet Josephson junctions in the nascent area of "superconducting spintronics."

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“…Very recently, Singh et al reported [9] the observation of a colossal triplet spin-valve effect for the S/F1/N/F2 structure made of amorphous MoGe, Ni, Cu, and CrO 2 as the S, F1, N, and F2 layers, respectively. This structure demonstrated variation of T c by ∼ 1 K when changing the relative alignment of the two F layers.…”

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confidence: 99%

Isolation of proximity-induced triplet pairing channel in a superconductor/ferromagnet spin valve

et al. 2016

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We have studied the proximity-induced superconducting triplet pairing in CoOx/Py1/Cu/Py2/Cu/Pb spin-valve structure (where Py = Ni0.81Fe0.19).By optimizing the parameters of this structure we found a triplet-channel assisted full switching between the normal and superconducting states. To observe an "isolated" triplet spin-valve effect we exploited the oscillatory feature of the magnitude of the ordinary spin-valve effect ∆Tc in the dependence of the Py2-layer thickness dP y2. We determined the value of dP y2 at which ∆Tc caused by the ordinary spin-valve effect (the difference in the superconducting transition temperature Tc between the antiparallel and parallel mutual orientation of magnetizations of the Py1 and Py2 layers) is suppressed. For such a sample a "pure" triplet spin-valve effect which causes the minimum in Tc at the orthogonal configuration of magnetizations has been observed.The superconducting spin-valve effect consists of different degree of suppression of superconductivity in the F1/F2/S or F1/S/F2 thin film multilayer constructions at parallel (P) and antiparallel (AP) mutual orientation of magnetizations of the F1 and F2 ferromagnetic layers. The superconducting spin valves based on the superconductor/ferromagnet (S/F) proximity effect offer a playground to explore fundamental aspects of interplay between superconductivity and magnetism and also promise applications as passive devices of the superconducting spintronics. The latter construction should be operational upon application of a small external magnetic field. Many experimental works were performed to confirm this effect for the S/F systems with a good contact between metallic F and S layers made of ordinary metals and standard ferromagnets (see, e.g., recent reviews [6]), the full switching between the superconducting and normal states has been realized only in a few cases [7,8] because ∆T c was usually smaller than the width of the superconducting transition δT c .Very recently, Singh et al. reported [9] the observation of a colossal triplet spin-valve effect for the S/F1/N/F2 structure made of amorphous MoGe, Ni, Cu, and CrO 2 as the S, F1, N, and F2 layers, respectively. This structure demonstrated variation of T c by ∼ 1 K when changing the relative alignment of the two F layers. It was shown that the optimal operational field for this device is of the order of 20 kOe. Gu et al. [10,11] reported ∆T c ∼ 400 mK for Ho/Nb/Ho trilayers. Also in this case the parallel configuration of magnetizations was reached at a field of ∼ 10 kOe. The high operational fields of these spin valves are disadvantageous for the superconducting spintronics. Besides, the physical reasons for large values of ∆T c for spin valve based on half-metals are not yet theoretically explained. This calls for elaboration of classical spinvalve structures which use standard ferromagnets (Fe, Co, Ni) and their alloys with good electrical contacts between all layers and for which theoretical understanding of the operational principle is available.Oh et al. [12] propos...

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Colossal Proximity Effect in a Superconducting Triplet Spin Valve Based on the Half-Metallic FerromagnetCrO2

Cited by 149 publications

References 24 publications

Cooper pair splitting in diffusive magnetic SQUIDs

Cooper pair splitting in diffusive magnetic SQUIDs

Amplitude Control of the Spin-Triplet Supercurrent inS/F/SJosephson Junctions

Isolation of proximity-induced triplet pairing channel in a superconductor/ferromagnet spin valve

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