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- Constantinian, K. Y., et al.
(författare)
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Electron transport and microwave dynamics of hybrid Nb/Au/CaSrCuO/YBaCuO planar Josephson junctions
- 2009
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 234:4, s. Art. no. 042004-
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Konferensbidrag (refereegranskat)abstract
- We report on measurements of dc electron transport and microwave dynamics of thin film hybrid Josephson junctions with an oxide antiferromagnetic interlayer. The base superconducting electrode YBaCuO and the antiferromagnetic (AF) interlayer CaSrCuO (with thickness d 20 - 70 nm) were grown by laser ablation on NdGaO3 substrates. I-V curves were well fitted to RSJ model and had no excess current, ICRN products were of order 0.2 mV at T=4.2 K. We did not observe any noticeable reduction of I CRN with increasing d. Such "tunnellike" behaviour also resulted in appearance of singularities on I-V curve when magnetic field was applied. Oscillating with microwave power integer and half-integer Shapiro steps were registered along with sub-harmonic detector response. Moreover, for some of junctions a "devil" staircase structure was observed on I-V curves and giant noise-like signals were measured in 1-2 GHz band at the certain levels of microwave power. Observed features, noise performance and the impact of the second harmonic in current-phase relation on junction dynamics are discussed taking into account data for structures without AF interlayer.
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| 2. |
- Kislinskiǐ, Yu V., et al.
(författare)
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Magnetically Dependent Superconducting Transport in Oxide Heterostructures with an Antiferromagnetic Layer
- 2008
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Ingår i: Journal of Experimental and Theoretical Physics. - 1090-6509 .- 1063-7761. ; 106:4, s. 800-805
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Tidskriftsartikel (refereegranskat)abstract
- The superconducting current in hybrid superconducting structuresNb/Au/Ca1−xSrxCuO2/YBa2Cu3O7 –δwith an antiferromagnetic layer is experimentally shown to have aJosephson nature, and the deviation from the sinusoidal dependence of the superconducting current on thephase difference between superconducting electrodes is about 20% of the second harmonic. These heterostructuresare found to have sensitivity to an applied magnetic field that is much higher than that of conventionalJosephson junctions. The experimental shape of the magnetic-field dependence of the critical current in the heterostructuresdiffers from the usual Fraunhofer shape by oscillation with a significantly smaller period along amagnetic field.PACS numbers: 74.45.+c, 74.50.+r, 75.70.Cn
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| 3. |
- Losev, A., et al.
(författare)
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From Zwiebach invariants to Getzler relation
- 2007
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Ingår i: Communications in Mathematical Physics. - : Springer Science and Business Media LLC. - 0010-3616 .- 1432-0916. ; 271:3, s. 649-679
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Tidskriftsartikel (refereegranskat)abstract
- We introduce the notion of Zwiebach invariants that generalize Gromov-Witten invariants and homotopical algebra structures. We outline the induction procedure that induces the structure of Zwiebach invariants on the sub-bicomplex, that gives the structure of Gromov-Witten invariants on sub-bicomplex with zero differentials. We propose to treat Hodge dGBV with 1/12 axiom as the simplest set of Zwiebach invariants, and explicitly prove that it induces WDVV and Getzler equations in genera 0 and 1 respectively.
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