| 1. |
- Kislinskiǐ, Yu V., et al.
(author)
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Copper oxide superconducting/antiferromagnetic interface
- 2015
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In: Solid State Phenomena. - 1662-9779 .- 1012-0394. - 9783038354826 ; 233-234, s. 733-736
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Conference paper (peer-reviewed)abstract
- Superconducting Nb/Au/Ca1-xSrxCuO2/YBa2Cu3O7 mesa-heterostructures were investigated. Dependencies of electrical parameters versus inverse capacitance were measured. A band diagram which takes into account an accumulation of holes inCa1-xSrxCuO2 interlayer and band bending due to difference of work functions was proposed. The dependencies of electrical parameters were analyzed by examining the quasipartical and superconducting currents.
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| 2. |
- Constantinian, K. Y., et al.
(author)
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Spin-Triplet Superconducting Current in Metal-Oxide Heterostructures With Composite Ferromagnetic Interlayer
- 2016
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In: IEEE Transactions on Applied Superconductivity. - : Institute of Electrical and Electronics Engineers (IEEE). - 1558-2515 .- 1051-8223. ; 26:3
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Journal article (peer-reviewed)abstract
- Superconducting heterostructures fabricated from oxide superconductor YBa2Cu2O7-delta and a composite ferromagnet La0.7Sr0.3MnO3/SrRuO3 interlayer and Au/Nb counter electrode were studied experimentally. Superconducting current was observed at magnetic field H raised up to 2000 Oe, which is greater than saturation magnetic field of manganite La0.7Sr0.3MnO3 (of order 100 Oe) and greater by a few orders than the value of magnetic field corresponding to penetration of one magnetic flux quantum. Microwave measurements of integer and half-integer Shapiro steps in conditions when relatively low external magnetic fieldH < 30 Oe was applied showed that the second harmonic in the current-phase relation of superconducting current becomes as big as the first harmonic. Fourier analysis of I-C(H) dependence allows extracting the components of fractional periods in I-C(H) function that also confirms a deviation from the sinusoidal current-phase relation. The obtained experimental data are explained by theoretical models that predict a huge enhancement of the second harmonic of the spin-triplet component in the superconducting current. The current-phase relation could be controlled by an external magnetic field, changing the directions of magnetization in the composite bilayer ferromagnet, which is inserted between two spin-singlet superconductors.
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| 3. |
- Sheyerman, A. E., et al.
(author)
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Current-phase relation of superconductor-ferromagnet-superconductor junctions with a composite interlayer
- 2015
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In: Solid State Phenomena. - 1662-9779 .- 1012-0394. ; 233-234, s. 737-740
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Conference paper (peer-reviewed)abstract
- We report on microwave measurements of hybrid superconductor-ferromagnetsuperconductor (SFF’S’) junctions with a composite oxide ferromagnetic bilayer with non-collinear magnetizations. Current-phase relation (CPR) of the junction superconducting current has been evaluated as a function of magnetic field. A significant part of the 2 nd harmonic in CPR, about 50%, was measured.
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| 4. |
- Sheyerman, A. E., et al.
(author)
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Spin-triplet electron transport in hybrid superconductor heterostructures with a composite ferromagnetic interlayer
- 2015
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In: Journal of Experimental and Theoretical Physics. - 1090-6509 .- 1063-7761. ; 120:6, s. 1024-1033
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Journal article (peer-reviewed)abstract
- Hybrid YBa2Cu3O7 - x /SrRuO3/La0.7Sr0.3MnO3/Au-Nb superconductor mesastructures with a composite manganite-ruthenate ferromagnetic interlayer are studied using electrophysical, magnetic, and microwave methods. The supercurrent in the mesastructure is observed when the interlayer thickness is much larger than the coherence length of ferromagnetic materials. The peak on the dependence of the critical current density on the interlayer material thickness corresponds to the coherence length, which is in qualitative agreement with theoretical predictions for a system with spit-triplet superconducting correlations. The magnetic-field dependence of the critical current is determined by penetration of magnetic flux quanta and by the magnetic domain structure, as well as by the field dependence of disorientation of the magnetization vectors of the layers in the composite magnetic interlayer. It is found that the supercurrent exists in magnetic fields two orders of magnitude stronger than the field corresponding to entry of a magnetic flux quantum into the mesastructure. The current-phase relation (CPR) of the supercurrent of mesastructures is investigated upon a change in the magnetic field from zero to 30 Oe; the ratio of the second CPR harmonic to the first, determined from the dependence of the Shapiro steps on the microwave radiation amplitude, does not exceed 50%.
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| 5. |
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