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108 results on '"Rouco, V"'

1. Disentangling photodoping, photoconductivity, and photosuperconductivity in the cuprates

Author

Hage, R. El, Sánchez-Manzano, D., Humbert, V., Carreira, S. J., Rouco, V., Sander, A, Cuellar, F., Seurre, K., Lagarrigue, A., Briatico, J., Trastoy, J., Santamaría, J., and Villegas, Javier E.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Strongly Correlated Electrons
Abstract

The normal-state conductivity and superconducting critical temperature of oxygen-deficient YBa2Cu3O7-x can be persistently enhanced by illumination. Strongly debated for years, the origin of those effects -- termed persistent photoconductivity (PPC) and photosuperconductivity (PPS) -- has remained an unsolved critical problem, whose comprehension may provide key insights to harness the origin of high-temperature superconductivity itself. Here we make essential steps toward understanding PPS. While the models proposed so far assume that it is caused by a carrier-density increase (photodoping) observed concomitantly, our experiments contradict such conventional belief: we demonstrate that it is instead linked to a photo-induced decrease of the electronic scattering rate. Furthermore, we find that the latter effect and photodoping are completely disconnected and originate from different microscopic mechanisms since they present different wavelength and oxygen-content dependencies as well as strikingly different relaxation dynamics. Besides helping disentangle photodoping, PPC, and PPS, our results provide new evidence for the intimate relation between critical temperature and scattering rate, a key ingredient in modern theories on high-temperature superconductivity.

Published
2023

3. Spin pumping in d-wave superconductor/ferromagnet hybrids

Author

Carreira, S. J., Sanchez-Manzano, D., Yoo, M. -W., Rouco, V., Sander, A., Santamaría, J., Anane, A., and Villegas, J. E.

Subjects
Condensed Matter - Materials Science
Abstract

Spin-pumping across ferromagnet/superconductor (F/S) interfaces has attracted much attention lately. Yet the focus has been mainly on s-wave superconductors-based systems whereas (high-temperature) d-wave superconductors such as YBa2Cu3O7-d (YBCO) have received scarce attention despite their fundamental and technological interest. Here we use wideband ferromagnetic resonance to study spin-pumping effects in bilayers that combine a soft metallic Ni80Fe20 (Py) ferromagnet and YBCO. We evaluate the spin conductance in YBCO by analyzing the magnetization dynamics in Py. We find that the Gilbert damping exhibits a drastic drop as the heterostructures are cooled across the normal-superconducting transition and then, depending on the S/F interface morphology, either stays constant or shows a strong upturn. This unique behavior is explained considering quasiparticle density of states at the YBCO surface, and is a direct consequence of zero-gap nodes for particular directions in the momentum space. Besides showing the fingerprint of d-wave superconductivity in spin-pumping, our results demonstrate the potential of high-temperature superconductors for fine tuning of the magnetization dynamics in ferromagnets using k-space degrees of freedom of d-wave/F interfaces., Comment: 20 pages, 6 figures

Published
2020
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4. Factors limiting ferroelectric field-effect doping in complex-oxide heterostructures

Author

Bégon-Lours, L., Rouco, V., Qiao, Qiao, Sander, A., Roldán, M. A., Bernard, R., Trastoy, J., Crassous, A., Jacquet, E., Bouzehouane, K., Bibes, M., Santamaría, J., Barthélémy, A., Varela, M., and Villegas, Javier E.

Subjects
Condensed Matter - Materials Science, Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Superconductivity
Abstract

Ferroelectric field-effect doping has emerged as a powerful approach to manipulate the ground state of correlated oxides, opening the door to a new class of field-effect devices. However, this potential is not fully exploited so far, since the size of the field-effect doping is generally much smaller than expected. Here we study the limiting factors through magneto-transport, scanning transmission electron and piezo-response force microscopy in ferroelectric/superconductor (YBa2Cu3O7-{\delta} /BiFeO3) heterostructures, a model system showing very strong field-effects. Still, we find that they are limited in the first place by an incomplete ferroelectric switching. This can be explained by the existence of a preferential polarization direction set by the atomic terminations at the interface. More importantly, we also find that the field-effect carrier doping is accompanied by a strong modulation of the carrier mobility. Besides making quantification of field-effects via Hall measurements not straightforward, this finding suggests that ferroelectric poling produces structural changes (e.g. charged defects or structural distortions) in the correlated oxide channel. Those findings have important consequences for the understanding of ferroelectric field-effects and for the strategies to further enhance them.

Published
2019
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5. A high-temperature superconducting weak-link defined by ferroelectric field-effect

Author

Begon-Lours, L., Rouco, V., Sander, A., Trastoy, J., Bernard, R., Jacquet, E., Bouzehouane, K., Fusil, S., Garcia, V., Barthelemy, A., Bibes, M., Santamaría, J., and Villegas, J. E.

Subjects
Condensed Matter - Superconductivity
Abstract

In all-oxide ferroelectric (FE) - superconductor (S) bilayers, due to the low carrier concentration of oxides compared to transition metals, the FE interfacial polarization charges induce an accumulation (or depletion) of charge carriers in the S. This leads either to an enhancement or a depression of its critical temperature depending on FE polarization direction.Here we exploit this effect at a local scale to define planar weak-links in high-temperature superconducting wires. This is realized in BiFeO3(FE)/YBa2Cu3O7(S)bilayers in which the remnant FE domain structure is written at will by locally applying voltage pulses with a conductive-tip atomic force microscope. In this fashion, the FE domain pattern defines a spatial modulation of superconductivity. This allows us to write a device whose electrical transport shows different temperature regimes and magnetic field matching effects that are characteristic of Josephson coupled weak-links. This illustrates the potential of the ferroelectric approach for the realization of high-temperature superconducting devices.

Published
2017
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6. Extremely long-range, high-temperature Josephson coupling across a half-metallic ferromagnet

Author

Sanchez-Manzano, D., Mesoraca, S., Cuellar, F. A., Cabero, M., Rouco, V., Orfila, G., Palermo, X., Balan, A., Marcano, L., Sander, A., Rocci, M., Garcia-Barriocanal, J., Gallego, F., Tornos, J., Rivera, A., Mompean, F., Garcia-Hernandez, M., Gonzalez-Calbet, J. M., Leon, C., Valencia, S., Feuillet-Palma, C., Bergeal, N., Buzdin, A. I., Lesueur, J., Villegas, Javier E., and Santamaria, J.

Published
2022
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7. Incipient Berezinskii-Kosterlitz-Thouless transition in two-dimensional coplanar Josephson junctions

Author

Massarotti, D., Jouault, B., Rouco, V., Charpentier, S., Bauch, T., Michon, A., De Candia, A., Lucignano, P., Lombardi, F., Tafuri, F., and Tagliacozzo, A.

Subjects
Condensed Matter - Superconductivity
Abstract

Superconducting hybrid junctions are revealing a variety of novel effects. Some of them are due to the special layout of these devices, which often use a coplanar configuration with relatively large barrier channels and the possibility of hosting Pearl vortices. A Josephson junction with a quasi ideal two-dimensional barrier has been realized by growing graphene on SiC with Al electrodes. Chemical Vapor Deposition offers centimeter size monolayer areas where it is possible to realize a comparative analysis of different devices with nominally the same barrier. In samples with a graphene gap below 400 nm, we have found evidence of Josephson coherence in presence of an incipient Berezinskii-Kosterlitz-Thouless transition. When the magnetic field is cycled, a remarkable hysteretic collapse and revival of the Josephson supercurrent occurs. Similar hysteresis are found in granular systems and are usually justified within the Bean Critical State model (CSM). We show that the CSM, with appropriate account for the low dimensional geometry, can partly explain the odd features measured in these junctions., Comment: 13 pages, 9 figures

Published
2016
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8. Disentangling photodoping, photoconductivity, and photosuperconductivity in the cuprates

Author

El Hage, R., Sánchez Manzano, David, Humbert, V., Carreira, S., Rouco, V., Sander, A., Cuéllar Jiménez, Fabian Andrés, Seurre, K., Lagarrigue, S. Mesoraca, A., Briatico, J., Trastoy, J., Santamaría Sánchez-Barriga, Jacobo, Villegas, J. E., El Hage, R., Sánchez Manzano, David, Humbert, V., Carreira, S., Rouco, V., Sander, A., Cuéllar Jiménez, Fabian Andrés, Seurre, K., Lagarrigue, S. Mesoraca, A., Briatico, J., Trastoy, J., Santamaría Sánchez-Barriga, Jacobo, and Villegas, J. E.

Abstract

The normal-state conductivity and superconducting critical temperature of oxygen-deficient YBa2Cu3O7-delta can be persistently enhanced by illumination. Strongly debated for years, the origin of those effects-termed persistent photoconductivity and photosuperconductivity (PPS)-has remained an unsolved critical problem, whose comprehension may provide key insights to harness the origin of hightemperature superconductivity itself. Here, we make essential steps toward understanding PPS. While the models proposed so far assume that it is caused by a carrier-density increase (photodoping) observed concomitantly, our experiments contradict such conventional belief: we demonstrate that it is instead linked to a photo-induced decrease of the electronic scattering rate. Furthermore, we find that the latter effect and photodoping are completely disconnected and originate from different microscopic mechanisms, since they present different wavelength and oxygen-content dependences as well as strikingly different relaxation dynamics. Besides helping disentangle photodoping, persistent photoconductivity, and PPS, our results provide new evidence for the intimate relation between critical temperature and scattering rate, a key ingredient in modern theories on high-temperature superconductivity., European Research Council, European Commission, Agence Natonale de la Recherche (France), Comunidad de Madrid, Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

Published
2024

9. Unusual magneto-transport of YBa2Cu3O7-d films due to the interplay of anisotropy, random disorder and nanoscale periodic pinning

Author

Trastoy, J., Rouco, V., Ulysse, C., Bernard, R., Palau, A., Puig, T., Faini, G., Lesueur, J., Briatico, J., and Villegas, J. E.

Subjects
Condensed Matter - Superconductivity, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We study the general problem of a manifold of interacting elastic lines whose spatial correlations are strongly affected by the competition between random and ordered pinning. This is done through magneto-transport experiments with YBa2Cu3O7-d thin films that contain a periodic vortex pinning array created via masked ion irradiation, in addition to the native random pinning. The strong field-matching effects we observe suggest the prevalence of periodic pinning, and indicate that at the matching field each vortex line is bound to an artificial pinning site. However, the vortex-glass transition dimensionality, quasi-2D instead of the usual 3D, evidences reduced vortex-glass correlations along the vortex line. This is also supported by an unusual angular dependence of the magneto-resistance, which greatly differs from that of Bose-glass systems. A quantitative analysis of the angular magnetoresistance allows us to link this behaviour to the enhancement of the system anisotropy, a collateral effect of the ion irradiation.

Published
2013
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10. Disentangling Photodoping, Photoconductivity, and Photosuperconductivity in the Cuprates

Author

El Hage, R., primary, Sánchez-Manzano, D., additional, Humbert, V., additional, Carreira, S., additional, Rouco, V., additional, Sander, A., additional, Cuellar, F., additional, Seurre, K., additional, Lagarrigue, A., additional, Mesoraca, S., additional, Briatico, J., additional, Trastoy, J., additional, Santamaría, J., additional, and Villegas, Javier E., additional

Published
2024
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12. Large Magnetoresistance of Isolated Domain Walls in La2/3Sr1/3MnO3 Nanowires

Author

Orfila G., Sanchez-Manzano D., Arora A., Cuellar F., Ruiz-Gómez S., Rodriguez-Corvillo S., López S., Peralta A., Carreira S.J., Gallego F., Tornos J., Rouco V., Riquelme J.J., Munuera C., Mompean F.J., Garcia-Hernandez M., Sefrioui Z., Villegas J.E., Perez L., Rivera-Calzada A., Leon C., Valencia S., Santamaria J., Orfila G., Sanchez-Manzano D., Arora A., Cuellar F., Ruiz-Gómez S., Rodriguez-Corvillo S., López S., Peralta A., Carreira S.J., Gallego F., Tornos J., Rouco V., Riquelme J.J., Munuera C., Mompean F.J., Garcia-Hernandez M., Sefrioui Z., Villegas J.E., Perez L., Rivera-Calzada A., Leon C., Valencia S., and Santamaria J.

Published
2023

13. Unconventional long range triplet proximity effect in planar YBa2Cu3O7/La0.7Sr0.3MnO3/YBa2Cu3O7 Josephson junctions

Author

Sanchez-Manzano D., Mesoraca S., Cuellar F., Cabero M., Rodriguez-Corvillo S., Rouco V., Mompean F., Garcia-Hernandez M., Gonzalez-Calbet J.M., Feuillet-Palma C., Bergeal N., Lesueur J., Leon C., Villegas J.E., Santamaria J., Sanchez-Manzano D., Mesoraca S., Cuellar F., Cabero M., Rodriguez-Corvillo S., Rouco V., Mompean F., Garcia-Hernandez M., Gonzalez-Calbet J.M., Feuillet-Palma C., Bergeal N., Lesueur J., Leon C., Villegas J.E., and Santamaria J.

Published
2023

14. Large Magnetoresistance of Isolated Domain Walls in La2/3Sr1/3MnO3 Nanowires

Author

Orfila, G., Sanchez-Manzano, D., Arora, A., Cuellar, F., Ruiz-Gómez, S., Rodriguez-Corvillo, S., López, S., Peralta, A., Carreira, S.J., Gallego, F., Tornos, J., Rouco, V., Riquelme, J.J., Munuera, C., Mompean, F. J., García-Hernández, Mar, Sefrioui, Zouhair, Villegas, J.E., Perez, L., Rivera-Calzada, Alberto, León, Carlos, Valencia, S., Santamaría, Jacobo, Orfila, G., Sanchez-Manzano, D., Arora, A., Cuellar, F., Ruiz-Gómez, S., Rodriguez-Corvillo, S., López, S., Peralta, A., Carreira, S.J., Gallego, F., Tornos, J., Rouco, V., Riquelme, J.J., Munuera, C., Mompean, F. J., García-Hernández, Mar, Sefrioui, Zouhair, Villegas, J.E., Perez, L., Rivera-Calzada, Alberto, León, Carlos, Valencia, S., and Santamaría, Jacobo

Abstract

Generation, manipulation, and sensing of magnetic domain walls are cornerstones in the design of efficient spintronic devices. Half-metals are amenable for this purpose as large low field magnetoresistance signals can be expected from spin accumulation at spin textures. Among half metals, La1−xSrxMnO3 (LSMO) manganites are considered as promising candidates for their robust half-metallic ground state, Curie temperature above room temperature (Tc = 360 K, for x = 1/3), and chemical stability. Yet domain wall magnetoresistance is poorly understood, with large discrepancies in the reported values and conflicting interpretation of experimental data due to the entanglement of various source of magnetoresistance, namely, spin accumulation, anisotropic magnetoresistance, and colossal magnetoresistance. In this work, the domain wall magnetoresistance is measured in LSMO cross-shape nanowires with single-domain walls nucleated across the current path. Magnetoresistance values above 10% are found to be originating at the spin accumulation caused by the mistracking effect of the spin texture of the domain wall by the conduction electrons. Fundamentally, this result shows the importance on non-adiabatic processes at spin textures despite the strong Hund coupling to the localized t2g electrons of the manganite. These large magnetoresistance values are high enough for encoding and reading magnetic bits in future oxide spintronic sensors. © 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.

Published
2023

15. A 2D ferroelectric vortex pattern in twisted BaTiO3 freestanding layers.

Author

Sánchez-Santolino, G., Rouco, V., Puebla, S., Aramberri, H., Zamora, V., Cabero, M., Cuellar, F. A., Munuera, C., Mompean, F., Garcia-Hernandez, M., Castellanos-Gomez, A., Íñiguez, J., Leon, C., and Santamaria, J.

Abstract

The wealth of complex polar topologies1–10 recently found in nanoscale ferroelectrics results from a delicate balance between the intrinsic tendency of the materials to develop a homogeneous polarization and the electric and mechanical boundary conditions imposed on them. Ferroelectric–dielectric interfaces are model systems in which polarization curling originates from open circuit-like electric boundary conditions, to avoid the build-up of polarization charges through the formation of flux-closure11–14 domains that evolve into vortex-like structures at the nanoscale15–17 level. Although ferroelectricity is known to couple strongly with strain (both homogeneous18 and inhomogeneous19,20), the effect of mechanical constraints21 on thin-film nanoscale ferroelectrics has been comparatively less explored because of the relative paucity of strain patterns that can be implemented experimentally. Here we show that the stacking of freestanding ferroelectric perovskite layers with controlled twist angles provides an opportunity to tailor these topological nanostructures in a way determined by the lateral strain modulation associated with the twisting. Furthermore, we find that a peculiar pattern of polarization vortices and antivortices emerges from the flexoelectric coupling of polarization to strain gradients. This finding provides opportunities to create two-dimensional high-density vortex crystals that would enable us to explore previously unknown physical effects and functionalities.The stacking of freestanding ferroelectric perovskite layers with controlled twist angles results in a peculiar pattern of polarization vortices and antivortices that emerges from the flexoelectric coupling of polarization to strain gradients. [ABSTRACT FROM AUTHOR]

Published
2024
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16. Light-Induced Decoupling of Electronic and Magnetic Properties in Manganites

Author

Navarro, H., primary, Basaran, Ali C., additional, Ajejas, F., additional, Fratino, L., additional, Bag, S., additional, Wang, T.D., additional, Qiu, E., additional, Rouco, V., additional, Tenreiro, I., additional, Torres, F., additional, Rivera-Calzada, A., additional, Santamaria, J., additional, Rozenberg, M., additional, and Schuller, Ivan K., additional

Published
2023
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17. Large Magnetoresistance of Isolated Domain Walls in LSMO Nanowires

Author

Orfila, Gloria, primary, Sanchez‐Manzano, David, additional, Arora, Ashima, additional, Cuellar, Fabian, additional, Ruiz‐Gómez, Sandra, additional, Rodriguez‐Corvillo, S., additional, López, Sandra, additional, Peralta, A., additional, Gallego, Fernando, additional, Tornos, J., additional, Rouco, V., additional, Riquelme, J. J., additional, Munuera, C., additional, Mompean, F., additional, Garcia‐Hernandez, M., additional, Sefrioui, Z., additional, Villegas, J. E., additional, Perez, L., additional, Rivera, A., additional, Leon, C., additional, Valencia, S., additional, and Santamaria, J., additional

Published
2023
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21. A 2D ferroelectric vortex pattern in twisted BaTiO3freestanding layers

Author

Sánchez-Santolino, G., Rouco, V., Puebla, S., Aramberri, H., Zamora, V., Cabero, M., Cuellar, F. A., Munuera, C., Mompean, F., Garcia-Hernandez, M., Castellanos-Gomez, A., Íñiguez, J., Leon, C., and Santamaria, J.

Abstract

The wealth of complex polar topologies1–10recently found in nanoscale ferroelectrics results from a delicate balance between the intrinsic tendency of the materials to develop a homogeneous polarization and the electric and mechanical boundary conditions imposed on them. Ferroelectric–dielectric interfaces are model systems in which polarization curling originates from open circuit-like electric boundary conditions, to avoid the build-up of polarization charges through the formation of flux-closure11–14domains that evolve into vortex-like structures at the nanoscale15–17level. Although ferroelectricity is known to couple strongly with strain (both homogeneous18and inhomogeneous19,20), the effect of mechanical constraints21on thin-film nanoscale ferroelectrics has been comparatively less explored because of the relative paucity of strain patterns that can be implemented experimentally. Here we show that the stacking of freestanding ferroelectric perovskite layers with controlled twist angles provides an opportunity to tailor these topological nanostructures in a way determined by the lateral strain modulation associated with the twisting. Furthermore, we find that a peculiar pattern of polarization vortices and antivortices emerges from the flexoelectric coupling of polarization to strain gradients. This finding provides opportunities to create two-dimensional high-density vortex crystals that would enable us to explore previously unknown physical effects and functionalities.

Published
2024
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22. Extremely long-range, high-temperature Josephson coupling across a half-metallic ferromagnet

Author

Sanchez-Manzano, D., primary, Mesoraca, S., additional, Cuellar, F. A., additional, Cabero, M., additional, Rouco, V., additional, Orfila, G., additional, Palermo, X., additional, Balan, A., additional, Marcano, L., additional, Sander, A., additional, Rocci, M., additional, Garcia-Barriocanal, J., additional, Gallego, F., additional, Tornos, J., additional, Rivera, A., additional, Mompean, F., additional, Garcia-Hernandez, M., additional, Gonzalez-Calbet, J. M., additional, Leon, C., additional, Valencia, S., additional, Feuillet-Palma, C., additional, Bergeal, N., additional, Buzdin, A. I., additional, Lesueur, J., additional, Villegas, Javier E., additional, and Santamaria, J., additional

Published
2021
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24. Extremely long-range, high-temperature Josephson coupling across a half-metallic ferromagnet

Author

Sánchez-Manzano D., Mesoraca S., Cuellar F.A., Cabero M., Rouco V., Orfila G., Palermo X., Balan A., Marcano L., Sander A., Rocci M., Garcia-Barriocanal J., Gallego F., Tornos J., Rivera A., Mompean F., Garcia-Hernandez M., Gonzalez-Calbet J.M., Leon C., Valencia S., Feuillet-Palma C., Bergeal N., Buzdin A.I., Lesueur J., Villegas J.E., Santamaría J., Sánchez-Manzano D., Mesoraca S., Cuellar F.A., Cabero M., Rouco V., Orfila G., Palermo X., Balan A., Marcano L., Sander A., Rocci M., Garcia-Barriocanal J., Gallego F., Tornos J., Rivera A., Mompean F., Garcia-Hernandez M., Gonzalez-Calbet J.M., Leon C., Valencia S., Feuillet-Palma C., Bergeal N., Buzdin A.I., Lesueur J., Villegas J.E., and Santamaría J.

Published
2021

25. Poster: Electronic Structure, Lattice Dynamics, and Transport

Author

Richter, Christoph, primary, Boschker, Hans, additional, Dietsche, Werner, additional, Mannhart, Jochen, additional, Brasse, M., additional, Jany, R., additional, Heyn, Ch., additional, Mannhart, J., additional, Wilde, M. A., additional, Grundler, D., additional, Tada, Masahiro, additional, Miyauchi, Yohei, additional, Yoshiya, Masato, additional, Yasuda, Hideyuki, additional, Sagarna, Leyre, additional, Maegli, Alexandra, additional, Yoon, Songhak, additional, Populoh, Sascha, additional, Shkabko, Andrey, additional, Weidenkaff, Anke, additional, Karthäuser, Silvia, additional, Manheller, Marcel, additional, Waser, Rainer, additional, Blech, Kerstin, additional, Simon, Ulrich, additional, Pengpan, T., additional, Boonthummo, A., additional, Togo, Atsushi, additional, Chaput, Laurent, additional, Tanaka, Isao, additional, Ramírez, M. A, additional, Simões, A. Z, additional, Longo, E., additional, Varela, J. A, additional, Xu, Pengxiang, additional, Schena, Timo, additional, Bihlmayer, Gustav, additional, Blügel, Stefan, additional, Thatribud, A., additional, Tungsurat, T., additional, Tan, X. L., additional, Chen, P. F., additional, Wang, L. F., additional, Zhi, B. W., additional, Wu, W. B., additional, Nikolaev, A. V., additional, Michel, K. H., additional, Tsvyashchenko, A. V., additional, Velichkov, A. I., additional, Salamatin, A. V., additional, Fomicheva, L. N., additional, Ryasny, G. K., additional, Sorokin, A. A., additional, Kochetov, O. I., additional, Budzynski, M., additional, Prieto, P., additional, Gómez, M. E., additional, Puig, T., additional, Obradors, X., additional, Palau, A., additional, Llordés, A., additional, Coll, M., additional, Vlad, R., additional, Gazquez, J., additional, Arbiol, J., additional, Guzmán, R., additional, Pomar, A., additional, Sandiumenge, F., additional, Ricart, S., additional, Rouco, V., additional, Ye, S., additional, Deutscher, G., additional, Chataigner, D., additional, Varela, M., additional, Magen, C., additional, Vanacken, J., additional, Gutierrez, J., additional, Moshchalkov, V. V., additional, Broglia, Giulia, additional, Montorsi, Monia, additional, Larcher, Luca, additional, Padovani, Andrea, additional, Nasr Esfahani, D., additional, Covaci, L., additional, Peeters, F. M., additional, Ohnishi, Hiromasa, additional, Kosugi, Taichi, additional, Miyake, Takashi, additional, Ishibashi, Shoji, additional, Terakura, Kiyoyuki, additional, Medarde, Marisa, additional, Straessle, Thierry, additional, Pomjakushin, Vladimir, additional, Martínez-Lope, María Jesus, additional, Alonso, José Antonio, additional, Nowak, R., additional, Chrobak, D., additional, Gerberich, W. W., additional, Niihara, K., additional, Wyrobek, T., additional, Estradé, S., additional, Rebled, J. M., additional, Walls, M. G., additional, de la Peña, F., additional, Colliex, C., additional, Córdoba, R., additional, Infante, I. C., additional, Herranz, G., additional, Sánchez, F., additional, Fontcuberta, J., additional, Peiró, F., additional, Velessiotis, D., additional, Douvas, A. M., additional, Dimitrakis, P., additional, Argitis, P., additional, Glezos, N., additional, Chrobak, Dariusz, additional, Gerberich, William W., additional, Nowak, Roman, additional, Meyer, Carola, additional, Spudat, C., additional, Müller, M., additional, Houben, L., additional, Maultzsch, J., additional, Goss, K., additional, Thomsen, C., additional, Schneider, C. M., additional, Reza Golobostanfard, Mohammad, additional, Abdizadeh, Hossein, additional, Schmidt, Manuel J., additional, Engels, Stephan, additional, Epping, Alexander, additional, Trellenkamp, Stefan, additional, Wichmann, Uwe, additional, Stampfer, Christoph, additional, Rocha, Paulo R. F., additional, Chen, Qian, additional, Kiazadeh, Asal, additional, Gomes, Henrique L., additional, Meskers, Stefan, additional, de Leeuw, Dago, additional, Paßens, Michael, additional, Busiakiewicz, Adam, additional, Franz, Adam W., additional, Barkschat, Christa S., additional, Urselmann, Dominik, additional, Müller, Thomas J. J., additional, Soltow, A., additional, Karthäuser, S., additional, Waser, R., additional, Zeng, Fei, additional, Yang, Jing, additional, Wang, Zhishun, additional, Lin, Yisong, additional, Li, Sizhao, additional, Hirschfeld, Julian A., additional, and Lustfeld, Hans, additional

Published
2013
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26. Ferroionic inversion of spin polarization in a spin-memristor

Author

Rouco, V., primary, Gallego, F., additional, Hernandez-Martin, D., additional, Sanchez-Manzano, D., additional, Tornos, J., additional, Beltran, J. I., additional, Cabero, M., additional, Cuellar, F., additional, Arias, D., additional, Sanchez-Santolino, G., additional, Mompean, F. J., additional, Garcia-Hernandez, M., additional, Rivera-Calzada, A., additional, Varela, M., additional, Muñoz, M. C., additional, Leon, C., additional, Sefrioui, Z., additional, and Santamaria, J., additional

Published
2021
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27. Controlled Sign Reversal of Electroresistance in Oxide Tunnel Junctions by Electrochemical-Ferroelectric Coupling

Author

Hernandez-Martin, D., primary, Gallego, F., additional, Tornos, J., additional, Rouco, V., additional, Beltran, J. I., additional, Munuera, C., additional, Sanchez-Manzano, D., additional, Cabero, M., additional, Cuellar, F., additional, Arias, D., additional, Sanchez-Santolino, G., additional, Mompean, F. J., additional, Garcia-Hernandez, M., additional, Rivera-Calzada, A., additional, Pennycook, S. J., additional, Varela, M., additional, Muñoz, M. C., additional, Sefrioui, Z., additional, Leon, C., additional, and Santamaria, J., additional

Published
2020
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28. Intrinsic anisotropy versus effective pinning anisotropy in YB a2 C u3 O7 thin films and nanocomposites

Author

Bartolome E., Valles F., Palau A., Rouco V., Pompeo N., Balakirev F. F., Maiorov B., Civale L., Puig T., Obradors X., Silva E., Bartolome, E., Valles, F., Palau, A., Rouco, V., Pompeo, N., Balakirev, F. F., Maiorov, B., Civale, L., Puig, T., Obradors, X., and Silva, E.

Subjects
Condensed Matter::Superconductivity
Abstract

The intrinsic and effective anisotropies, both in the liquid and solid vortex regimes, of YBa2Cu3O7 (YBCO) pristine and nanocomposite thin films have been investigated. Angular resistivity measurements under varying fields and temperatures were performed to characterize the intrinsic vs effective anisotropy of samples in the regime of long-range vortex displacements. The effective anisotropy γeff was determined from the scaling of the irreversibility line, applying the Blatter approach developed for uniaxial anisotropic superconductors. Resistive measurements in flux flow were utilized, in addition to Hc2 measurements in ultrahigh-fields, to determine the intrinsic anisotropy mass γ, enabling the study of a large number of samples with varied nanoparticle compositions. In order to access the intrinsic anisotropy in the vortex solid phase, complex impedance measurements at high microwave frequencies were performed, allowing us to access the flux-flow intrinsic anisotropy in the regime of very short vortex oscillations within the pinning potential wells. Results show that while the effective anisotropy γeff decays as the nanoparticles-induced nanostrain in the YBCO films increases, the intrinsic anisotropy γ (determined both in dc and at microwave frequency) remains unaltered.

Published
2019

29. Quasiparticle tunnel electroresistance in superconducting junctions

Author

Grandal, Javier, León Yebra, Carlos, Varela del Arco, María, Santamaría Sánchez-Barriga, Jacobo, Rouco, V., El Hage, R., Sander, A., Seurre, K., Palermo, X., Briatico, J., Grandal, Javier, León Yebra, Carlos, Varela del Arco, María, Santamaría Sánchez-Barriga, Jacobo, Rouco, V., El Hage, R., Sander, A., Seurre, K., Palermo, X., and Briatico, J.

Abstract

©2020 Nature Publishing Group Artículo escrito por más de diez autores. ERCEuropean Research Council (ERC) [647100]; French ANRFrench National Research Agency (ANR) [ANR-15-CE24-0008-01, ANR-16-CE24-0028-01]; European COST action [16218]; Spanish MINECO-FEDER [MAT2015-66888-C3-3-R]; ERC PoC2016 POLAR-EM; Quantox of QuantERA ERA-NET Cofund in Quantum Technologies [731473]; European Union's Horizon 2020 research and innovation programme (Marie Sklodowska-Curie IF grant agreement OXWALD)European Union (EU) [838693]; IDEX Paris-Saclay [ANR-11-IDEX-0003-02], The term tunnel electroresistance (TER) denotes a fast, non-volatile, reversible resistance switching triggered by voltage pulses in ferroelectric tunnel junctions. It is explained by subtle mechanisms connected to the voltage-induced reversal of the ferroelectric polarization. Here we demonstrate that effects functionally indistinguishable from the TER can be produced in a simpler junction scheme-a direct contact between a metal and an oxide-through a different mechanism: a reversible redox reaction that modifies the oxide's ground-state. This is shown in junctions based on a cuprate superconductor, whose ground-state is sensitive to the oxygen stoichiometry and can be tracked in operando via changes in the conductance spectra. Furthermore, we find that electrochemistry is the governing mechanism even if a ferroelectric is placed between the metal and the oxide. Finally, we extend the concept of electroresistance to the tunnelling of superconducting quasiparticles, for which the switching effects are much stronger than for normal electrons. Besides providing crucial understanding, our results provide a basis for non-volatile Josephson memory devices. The non-volatile switching of tunnel electroresistance in ferroelectric junctions provides the basis for memory and neuromorphic computing devices. Rouco et al. show tunnel electroresistance in superconductor-based junctions that arises from a redox rather than ferroelectric mechanism and is enhanced by superconductivity., Unión Europea. Horizonte 2020, Ministerio de Economía y Competitividad (MINECO) /FEDER, European COST Action, French National Research Agency (ANR), M-ERA.Net, IDEX Paris-Saclay, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

Published
2020

30. Strain-driven broken twin boundary coherence in YBa2Cu3O7−δ nanocomposite thin films

Author

Guzman, R., Gazquez, J., Rouco, V., Palau, A., Magén, C., Varela, M., Arbiol, J., Obradors, X., and Puig, T.

Abstract

In this letter we use high resolution scanning transmission electron microscopy to study epitaxial YBa2Cu3O7-d (YBCO) nanocomposite thin films. We find that twin boundaries (TB) in YBCO nanocomposite thin films are disturbed by the presence of secondary phase nanoparticles as well as by intergrowths. Secondary phases promote the nucleation of TBs and, at the same time, result in bending, decreasing and changing the TB's spacing. On the other hand, the local strain ensuing from the partial dislocation associated to Y248 and Y125 intergrowths break the vertical coherence of TBs. This interaction results in a complex domain structure where twin boundary coherence is no longer satisfied and twin spacing is reduced down to a few nanometers precluding vortex channeling at low temperatures.

Published
2018

32. Ferroelectric Control of Interface Spin Filtering in Multiferroic Tunnel Junctions

Author

European Commission, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Comunidad de Madrid, Tornos, J., Gallego, F., Valencia, S., Liu, Y. H., Rouco, V., Lauter, V., Abrudan, R., Luo, C., Ryll, H., Wang, Q., Hernandez-Martin, D., Orfila, G., Cabero, Mariona, Cuellar, Fabián A., Arias, D., Mompean, F. J., García-Hernández, Mar, Radu, F., Charlton, T.R., Rivera-Calzada, A., Sefrioui, Z., Te Velthuis, S. G. E., León, Carlos, Santamaría, Jacobo, European Commission, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Comunidad de Madrid, Tornos, J., Gallego, F., Valencia, S., Liu, Y. H., Rouco, V., Lauter, V., Abrudan, R., Luo, C., Ryll, H., Wang, Q., Hernandez-Martin, D., Orfila, G., Cabero, Mariona, Cuellar, Fabián A., Arias, D., Mompean, F. J., García-Hernández, Mar, Radu, F., Charlton, T.R., Rivera-Calzada, A., Sefrioui, Z., Te Velthuis, S. G. E., León, Carlos, and Santamaría, Jacobo

Abstract

[EN] The electronic reconstruction occurring at oxide interfaces may be the source of interesting device concepts for future oxide electronics. Among oxide devices, multiferroic tunnel junctions are being actively investigated as they offer the possibility to modulate the junction current by independently controlling the switching of the magnetization of the electrodes and of the ferroelectric polarization of the barrier. In this Letter, we show that the spin reconstruction at the interfaces of a La0.7Sr0.3MnO3/BaTiO3/La0.7Sr0.3MnO3 multiferroic tunnel junction is the origin of a spin filtering functionality that can be turned on and off by reversing the ferroelectric polarization. The ferroelectrically controlled interface spin filter enables a giant electrical modulation of the tunneling magnetoresistance between values of 10% and 1000%, which could inspire device concepts in oxides-based low dissipation spintronics.

Published
2019

33. Competition between Superconductor-Ferromagnetic stray magnetic fields in YBa2Cu3O7-x films pierced with Co nano-rods

Author

Rouco, V., Córdoba, R., De Teresa, J.M., Rodríguez, L.A., Navau, C., Del-Valle, N., Via, G., Sánchez, A., Monton, C., Kronast, F., Obradors, X., Puig, T., and Palau, A.

Subjects
Condensed Matter::Materials Science, Condensed Matter::Superconductivity
Abstract

Superconductivity and ferromagnetism are two antagonistic phenomena that combined can lead to a rich phenomenology of interactions, resulting in novel physical properties and unique functionalities. Here we propose an original hybrid system formed by a high-Temperature superconducting film, patterned with antidots, and with ferromagnetic nano-rods grown inside them. This particular structure exhibits the synergic influence of superconductor (SC)-ferromagnetic (FM) stray fields, in both the superconducting behaviour of the film and the three-dimensional (3D) magnetic structure of nano-rods. We show that FM stray fields directly influence the critical current density of the superconducting film. Additional functionalities appear due to the interaction of SC stray fields, associated to supercurrent loops, with the non-Trivial 3D remanent magnetic structure of FM nano-rods. This work unravels the importance of addressing quantitatively the effect of stray magnetic fields from both, the superconductor and the ferromagnet in hybrid magnetic nano-devices based on high temperature superconductors.

Published
2017

34. Ferroelectric Control of Interface Spin Filtering in Multiferroic Tunnel Junctions

Author

Tornos, J., primary, Gallego, F., additional, Valencia, S., additional, Liu, Y. H., additional, Rouco, V., additional, Lauter, V., additional, Abrudan, R., additional, Luo, C., additional, Ryll, H., additional, Wang, Q., additional, Hernandez-Martin, D., additional, Orfila, G., additional, Cabero, M., additional, Cuellar, F., additional, Arias, D., additional, Mompean, F. J., additional, Garcia-Hernandez, M., additional, Radu, F., additional, Charlton, T. R., additional, Rivera-Calzada, A., additional, Sefrioui, Z., additional, te Velthuis, S. G. E., additional, Leon, C., additional, and Santamaria, J., additional

Published
2019
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35. Factors limiting ferroelectric field-effect doping in complex oxide heterostructures

Author

Bégon-Lours, L., primary, Rouco, V., additional, Qiao, Qiao, additional, Sander, A., additional, Roldán, M. A., additional, Bernard, R., additional, Trastoy, J., additional, Crassous, A., additional, Jacquet, E., additional, Bouzehouane, K., additional, Bibes, M., additional, Santamaría, J., additional, Barthélémy, A., additional, Varela, M., additional, and Villegas, Javier E., additional

Published
2018
Full Text
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39. Competition between Superconductor – Ferromagnetic stray magnetic fields in YBa2Cu3O7−x films pierced with Co nano-rods

Author

Rouco, V., primary, Córdoba, R., additional, De Teresa, J. M., additional, Rodríguez, L. A., additional, Navau, C., additional, Del-Valle, N., additional, Via, G., additional, Sánchez, A., additional, Monton, C., additional, Kronast, F., additional, Obradors, X., additional, Puig, T., additional, and Palau, A., additional

Published
2017
Full Text
View/download PDF

41. Competition between Superconductor - Ferromagnetic stray magnetic fields in YBa2Cu3O7-x films pierced with Co nano-rods

Author

Rouco, V, Córdoba, R, De Teresa, J M, Rodríguez, L A, Navau, C, Del-Valle, N, Via, G, Sánchez, A, Monton, C, Kronast, F, Obradors, X, Puig, T, Palau, A; https://orcid.org/0000-0002-2217-164X, Rouco, V, Córdoba, R, De Teresa, J M, Rodríguez, L A, Navau, C, Del-Valle, N, Via, G, Sánchez, A, Monton, C, Kronast, F, Obradors, X, Puig, T, and Palau, A; https://orcid.org/0000-0002-2217-164X

Abstract

Superconductivity and ferromagnetism are two antagonistic phenomena that combined can lead to a rich phenomenology of interactions, resulting in novel physical properties and unique functionalities. Here we propose an original hybrid system formed by a high-temperature superconducting film, patterned with antidots, and with ferromagnetic nano-rods grown inside them. This particular structure exhibits the synergic influence of superconductor (SC) - ferromagnetic (FM) stray fields, in both the superconducting behaviour of the film and the three-dimensional (3D) magnetic structure of nano-rods. We show that FM stray fields directly influence the critical current density of the superconducting film. Additional functionalities appear due to the interaction of SC stray fields, associated to supercurrent loops, with the non-trivial 3D remanent magnetic structure of FM nano-rods. This work unravels the importance of addressing quantitatively the effect of stray magnetic fields from both, the superconductor and the ferromagnet in hybrid magnetic nano-devices based on high temperature superconductors.

Published
2017

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