Información del autor
Autor Vicent López, José Luis |
Documentos disponibles escritos por este autor (57)
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Vélez, M. ; González Herrera, Elvira María ; Martín, J. I. ; Vicent López, José Luis | American Physical Society | 1996-07-01?-axis-oriented EuBa_2Cu_3O_7/PrBa_2Cu_3O_7 (EBCO/PBCO) superlattices allow us to separate contributions to the anisotropy coming from the natural layered structure of EBCO from that introduced by the artificial layering with PBCO. The angular d[...]texto impreso
Jaque, D. ; González Herrera, Elvira María ; Martín, J. I. ; Anguita,, J. V. ; Vicent López, José Luis | American Institute of Physics | 2002-10-07Arrays of submicrometric Ni lines have been fabricated in superconducting Nb films by electron beam lithography. In the mixed state, these arrays induce strong anisotropy in the dissipation behavior. The dissipation is reduced several orders of [...]texto impreso
González Herrera, Elvira María ; Villegas, J. E. ; Varela del Arco, María ; Santamaría Sánchez-Barriga, Jacobo ; Prieto, P. ; Schuller, Ivan K. ; Vicent López, José Luis | American Institute of Physics | 2002-05-27Bi_2Sr_2CaCu_2O_8, RBa_2Cu_3O_7 (R=Y, Eu) thin films and RBa_2Cu_3O_7/PrBa_2Cu_3O_7 superlattices have been fabricated by sputtering technique. The anisotropic dissipation was measured close to the critical temperatures with high applied magneti[...]texto impreso
Gómez Nicola, Ángel ; Cebollada, F. ; Palomares, F. J. ; Sánchez, N. ; González Herrera, Elvira María ; González, J. M. ; Vicent López, José Luis | American Institute of Physics | 2014-03-10In this work, we improve the ability to tailor the switching mechanism in nanomagnets by introducing an additional, highly controlled source of anisotropy: magnetocrystalline anisotropy. We analyze the vortex dynamics in single crystal Fe nanotr[...]texto impreso
Gómez Nicola, Ángel ; Gilbert, D. A. ; González Herrera, Elvira María ; Liu, Kai ; Vicent López, José Luis | American Institute of Physics | 2013-02-04Hybrid superconducting/magnetic nanostructures on Si substrates have been built with identical physical dimensions but different magnetic configurations. By constructing arrays based on Co-dots with in-plane, out-of-plane, and vortex state magne[...]texto impreso
Jaafar, M. ; Yanes,, R. ; Pérez de Lara, D. ; Chubykalo Fesenko, O. ; Asenjo, A. ; González Herrera, Elvira María ; Anguita, J. V. ; Vázquez, V. ; Vicent López, José Luis | American Physical Society | 2010-02Magnetic vortex dynamics in lithographically prepared nanodots is currently a subject of intensive research, particularly after recent demonstration that the vortex polarity can be controlled by in-plane magnetic field. This has stimulated the p[...]texto impreso
Dinis Vizcaíno, Luis Ignacio ; González Herrera, Elvira María ; Anguita, J. V. ; Parrondo, J. M. R. ; Vicent López, José Luis | American Physical Society | 2007-12A collective mechanism for current reversal in superconducting vortex ratchets is proposed. The mechanism is based on a two-dimensional instability of the ground state (T=0) of the system. We illustrate our results with numerical simulations and[...]texto impreso
Villegas, J. E. ; González Herrera, Elvira María ; Montero,, M. I. ; Schuller, Ivan K. ; Vicent López, José Luis | American Physical Society | 2003-12Rectangular pinning arrays of Ni dots define a potential landscape for vortex motion in Nb films. Magnetotransport experiments in which two in-plane orthogonal electrical currents are injected simultaneously allow one to select the direction and[...]texto impreso
Perez de Lara, Daniel ; Alija, A. ; González Herrera, Elvira María ; Martín, J. I. ; Vélez, M. ; Colino, J. L. ; Anguita,, J. V. ; Vicent López, José Luis | American Institute of Physics | 2009-03-23Superconducting a-Mo_(3)Si and Nb films have been grown on arrays of Ni nanodots. We have studied the vortex lattice dynamics close to critical temperatures. Different vortex lattice configurations are obtained with the same array unit cell. The[...]texto impreso
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Villegas, J. E. ; Nuñez, N. O. ; González Herrera, Elvira María ; González, M. P. ; Vicent López, José Luis | Indian Academy Sciences | 2006-01Nb films grown on top of an array of asymmetric pinning centers show a vortex ratchet effect. A net flow of vortices is induced when the vortex lattice is driven by fluctuating forces on an array of pinning centers without reflection symmetry. [...]texto impreso
Villegas, J. E. ; González Herrera, Elvira María ; González, M. P. ; Anguita, J. V. ; Vicent López, José Luis | American Physical Society | 2005-01A vortex lattice ratchet effect has been investigated in Nb films grown on arrays of nanometric Ni triangles, which induce periodic asymmetric pinning potentials. The vortex lattice motion yields a net dc voltage when an ac driving current is ap[...]texto impreso
Valle Granda, Javier del ; Gómez, A. ; González, E. M. ; Osorio, M. R. ; Gálvez Alonso, Fernando ; Granados, D. ; Vicent López, José Luis | IOP Publishing | 2015-09-14Smectic order has been generated in superconducting Nb films with two-fold symmetry arrays of symmetric pinning centers. Magnetic fields applied perpendicularly to the films develop a vortex matter smectic phase that is easily detected when the [...]texto impreso
Gálvez Alonso, Fernando ; Pérez de Lara, D. ; García, M. A. ; Vicent López, José Luis | Elsevier Sci. Ltd | 2017-12We present here an experimental set-up system to excite and measure simultaneously surface plasmon resonance (SPR) and magneto-optic signal in hybrid magneto-plasmonic systems using two independent light sources. The system can be used to excite[...]texto impreso
Villegas, J. E. ; González Herrera, Elvira María ; González, M. P. ; Nuñez, N. O. ; Anguita, J. V. ; Vicent López, José Luis | Amer Inst Physics | 2006Superconducting Nb thin films were grown on different arrays of triangle-shape metallic islands. The vortex lattice dynamics could be strongly modified by these asymmetric vortex traps. These asymmetric pinning potentials lead to a rectification[...]texto impreso
Pérez de Lara, D. ; González Herrera, Elvira María ; Vicent López, José Luis | American Physical Society | 2010-11-19The superconducting and magnetic properties of a-Co_(x)Si_(1?x) /Nb bilayers have been studied as a function of Co content in order to analyze the superconducting/ferromagnetic proximity effect in a system with strong disorder in the magnetic la[...]texto impreso
Valle Granda, Javier del ; Gómez Nicola, Ángel ; González Herrera, Elvira María ; Mañas Baena, Manuel ; Coronado, E. ; Vicent López, José Luis | American Physical Society | 2017-06-12Superconducting 2H-NbSe_2 single crystals show intrinsic low pinning values. Therefore, they are ideal materials with which to explore fundamental properties of vortices. (V, I) characteristics are the experimental data we have used to investiga[...]texto impreso
Gálvez Alonso, Fernando ; Pérez de Lara, D. ; Spottorno Giner, Jorge ; García, M. A. ; Vicent López, José Luis | Elsevier Science S A | 2017-05We present here a study of the possible local heating effects in surface plasmon resonance sensors using low power lasers (?mW/mm_2). By measuring the increase of electrical resistivity in an Au stripe while exciting SPR and performing numerical[...]texto impreso
Ruiz-Valdepeñas Martín de Almagro, Luis ; Vélez, M. ; Valdés Bango, F. ; Álvarez Prado, L.M. ; García Alonso, F.J. ; Martín, J.I. ; Navarro Palma, Elena ; Alameda, J.M. ; Vicent López, José Luis | American Institute of Physics | 2014-06-07Magnetization reversal processes have been studied in hybrid magnetic/superconducting Nd-Co/Nb bilayers by the comparison of out-of-plane magnetic hysteresis loops and superconducting phase diagrams as a function of magnetic layer thickness and [...]texto impreso
Díaz-Guerra Viejo, Carlos ; Vicent López, José Luis ; Piqueras de Noriega, Javier ; Dieguez, E. | IOP publishing ltd | 2007-01-07The influence of the doping level on the radiative recombination properties of GaSb:Se crystals has been investigated by cathodoluminescence (CL) microscopy and spectroscopy in the scanning electron microscope. CL images evidence a high dislocat[...]texto impreso
Villegas, J. E. ; Sefrioui, Zouhair ; Varela del Arco, María ; González Herrera, Elvira María ; Santamaría Sánchez-Barriga, Jacobo ; Vicent López, José Luis | American Physical Society | 2004-04We study angular dependent magnetoresistance in the vortex-liquid phase of epitaxial YBa2Cu3O7 thin films and YBa_2Cu_3O_7/PrBa_2Cu_3O_7 superlattices. Superlattices were grown with different PrBa_2Cu_3O_7 thickness in order to tune coupling bet[...]texto impreso
González Herrera, Elvira María ; González Casado, J.M. ; Vicent López, José Luis | American Physical Society | 2000-10-01a-axis oriented (CuO_2 planes perpendicular to the substrate) films and superlattices grown on cubic substrates show a structure with 90° microdomains. The microdomains are grains with a 90° rotation of the c axis. In the vortex liquid region, t[...]texto impreso
Dinis Vizcaíno, Luis Ignacio ; González Herrera, Elvira María ; Anguita, J. V. ; Parrondo, J. M. R. ; Vicent López, José Luis | IOP Publishing | 2007-10-09Competition between the vortex lattice and a lattice of asymmetric artificial defects is shown to play a crucial role in ratchet experiments in superconducting films. We present a novel and collective mechanism for current reversal based on a re[...]texto impreso
Dinis Vizcaíno, Luis Ignacio ; González Herrera, Elvira María ; Anguita, J. V. ; Rodríguez Parrondo, Juan Manuel ; Vicent López, José Luis | IOP Publishing | 2007-10-09Competition between the vortex lattice and a lattice of asymmetric artificial defects is shown to play a crucial role in ratchet experiments in superconducting films. We present a novel and collective mechanism for current reversal based on a re[...]texto impreso
Gálvez, F. ; Valle, J. del ; Gómez Gutiérrez, Alicia ; González Herrera, Elvira María ; Navarro Palma, Elena ; Vicent López, José Luis ; Soriano, N. ; Mora, B. ; Rollano, V. ; Gargiani, P. | American Institute of Physics | 2020-06-01The development of multilayered materials with engineered magnetic properties compels a deep knowledge of physical properties at the atomic scale. The magnetic anisotropy is a key property in these materials. This work accounts for the magnetic [...]texto impreso
Ory, M.C. de ; Rollano, V. ; Gómez, A. ; Menghini, M. ; Muñoz Noval, Álvaro ; González Herrera, Elvira María ; Vicent López, José Luis | Nature Publishing Group | 2020-06-25Little-Parks effect names the oscillations in the superconducting critical temperature as a function of the magnetic field. This effect is related to the geometry of the sample. In this work, we show that this effect can be enhanced and manipula[...]texto impreso
Joshi, Amish G ; Kryukov, Sergiy A. ; De Long, Lance E. ; González Herrera, Elvira María ; Navarro Palma, Elena ; Villegas, Javier E. ; Vicent López, José Luis | American Institute of Physics | 2007-05-01We report vibrating reed and superconducting quantum interference device magnetometer data that exhibit prominent dips or oscillations of the superconducting (SC) onset temperature, Delta T(C)(H)approximate to 0.01-0.7 K, for a [Nb(23 nm)/Ni(5 n[...]texto impreso
We have studied two nanomagnet systems with strong (Co/Pd multilayers) and weak (NdCo alloy films) stray magnetic fields by probing the out-of-plane magnetic states with superconducting vortices. The hybrid samples are made of array of nanomagne[...]texto impreso
Navarro Palma, Elena ; Vélez, M. ; Huttel, Y. ; Pérez Junquera, A. ; Martín, J. Y. ; Lima, O. F. de ; Cebollada, A. ; Alameda, J. M. ; Vicent López, José Luis | American Institute of Physics | 2009-02-01Shifted hysteresis loops characteristic of the exchange bias effect between a ferromagnet and an antiferromagnet are demonstrated in structures formed by a 2.5 nm Cr layer deposited on top of an array of Fe nanoislands (Cr/Fe-nanoislands). This [...]texto impreso
Pérez de Lara, David ; Castaño, F. J. ; Ng, B. G. ; Körner, H. S. ; Dumas, R. K. ; González Herrera, Elvira María ; Liu, Kai ; Ross,, C. A. ; Schuller, Ivan K. ; Vicent López, José Luis | American Institute of Physics | 2011-10-31Strong superconducting pinning effects are observed from magnetic landscapes produced by arrays of circular rings with varying magnetic remanent states. The collective and the background pinning of superconducting Nb films is strongly enhanced b[...]texto impreso
González Herrera, Elvira María ; Montero, M. I. ; Cebollada, F. ; De Julián Fernández, C ; Vicent López, José Luis ; González, J. M. | E D P Sciences | 1998-04-01We analyze the magnetic properties of mechanically ground nanosized Ni particles dispersed in a SiO_2 matrix. Our magnetic characterization of the as-milled samples show the occurrence of two blocking processes and that of non-monotonic milling [...]texto impreso
Valle Granda, Javier del ; Gómez, A. ; González, E. M. ; Vicent López, José Luis | American Institute of Physics | 2016-10-24In order to compare magnetic and non-magnetic pinning, we have nanostructured two superconducting films with the regular arrays of pinning centers: Cu (non-magnetic) dots in one case and Py (magnetic) dots in the other. For low applied magnetic [...]texto impreso
Ruiz Valdepenas, L. ; Navarro Palma, Elena ; Vicent López, José Luis | American Institute of Physics | 2012-10-15Nd-Co amorphous magnetic films with perpendicular magnetic anisotropy have been grown on nanostructured templates prepared with self-organized di-block poly(styrene)-block-poly(4-vinylpyridine) copolymer layers with a periodic structure of 60 nm[...]texto impreso
Gálvez Alonso, Fernando ; Valle Granda, Javier del ; Gómez, A. ; Osorio, M. R. ; Granados, D. ; Pérez de Lara, D. ; Garcia, M.A. ; Vicent López, José Luis | Optical Soc Amer | 2016-10-01We have designed and fabricated a nanodevice exhibiting simultaneously ferromagnetic properties of nanostructures with plasmonic properties of continuous films. Our device consists of an array of nanomagnets on top of a continuous plasmonic film[...]texto impreso
Gómez Gutiérrez, Alicia ; González Herrera, Elvira María ; Vicent López, José Luis ; Cebollada Barata, Federico A. ; Palomares Simón, Francisco Javier ; Sánchez Agudo, Marta ; Urdiroz Urricelqui, Unai | IOP publishing ltd | 2019-02-27With the aim of achieving stable, substantial remanences adequate for exploitation in stray field-based applications, we report on the hysteresis behavior occurring in arrays of single-crystal Fe motifs, a-beam lithographed into prisms with tria[...]texto impreso
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Pérez de Lara, David ; Castaño, F. J. ; Ng,, B. G. ; Körner, H. S. ; Dumas, R. K. ; González Herrera, Elvira María ; Liu, Kai ; Ross,, C. A. ; Schuller, Ivan K. ; Vicent López, José Luis | American Physical Society | 2009-12A ratchet effect (the rectification of an ac injected current) which is purely magnetic in origin has been observed in a superconducting-magnetic nanostructure hybrid. The hybrid consists of a superconducting Nb film in contact with an array of [...]texto impreso
Vicent López, José Luis ; Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Dieguez, E. | Elsevier Science B.V. | 2006-08-01Dilute Te-doped GaSb alloys have been prepared by the vertical feeding method (VFM) using both casting and feeding configurations. The structural and optical properties of the samples were characterized by etching, X-ray diffraction and cathodol[...]texto impreso
González Herrera, Elvira María ; Folgueras, A. D. ; Escudero, R. ; Ferrer, J.M. ; Guinea, F. ; Vicent López, José Luis | IOP Publishing | 2007-02-21We have measured the tunnelling current in Nb/Nb_xO_y/Ni planar tunnel junctions at different temperatures. The junctions are in the intermediate transparency regime. We have extracted the current polarization of the metal/ferromagnet junction w[...]texto impreso
Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Vicent López, José Luis | Amer Inst Physics | 1990-12-17Changes in the visible and infrared cathodoluminescence(CL)spectra of YBa2Cu3O7?x are detected during irradiation in the scanning electron microscope. Results indicate the influence of oxygen content on the appearance of a CL band at 450–600 nm.[...]texto impreso
Valle Granda, Javier del ; Gómez, A. ; González, E. M. ; Osorio, M. R. ; Granados, D. ; Vicent López, José Luis | Nature Publishing Group | 2015-10We present a simple nanodevice that can operate in two modes: i) non-volatile three-state memory and ii) reading device. The nanodevice can retain three well defined states ?1, 0 and +1 and can operate in a second mode as a sensor for external m[...]texto impreso
De Long, LE ; Kryukov, S. A. ; Bosomtwi, A. ; Xu, WT ; González Herrera, Elvira María ; Navarro Palma, Elena ; Villegas, J. E. ; Vicent López, José Luis ; Yu, Ct ; Pechan, MJ | Taylor & Francis Ltd | 2006-06-11The temperature and field dependences of the AC and DC magnetic moment of superconducting and ferromagnetic Nb/Ni multilayers were measured using a SQUID magnetometer with magnetic field applied parallel to the multilayer plane. Periodic kinks i[...]texto impreso
Rollano, V. ; Muñoz Noval, Álvaro ; Gómez, A. ; Valdés Bango, F. ; Martín, J.I. ; Vélez, M. ; Osorio, M. R. ; Granados, D. ; González Herrera, Elvira María ; Vicent López, José Luis | IOP publishing ltd | 2019-06-14We have designed, fabricated and tested a robust superconducting ratchet device based on topologically frustrated spin ice nanomagnets. The device is made of a magnetic Co honeycomb array embedded in a superconducting Nb film. This device is bas[...]texto impreso
Dinis, L. ; Perez de Lara, Daniel ; González Herrera, Elvira María ; Anguita, J. V. ; Parrondo, J. M. R. ; Vicent López, José Luis | IOP Publishing | 2009-07-23A transverse ratchet effect has been measured in magnetic/ superconducting hybrid films fabricated by electron beam lithography and magnetron sputtering techniques. The samples are Nb films grown on top of an array of Ni nanotriangles. Injecting[...]texto impreso
González Herrera, Elvira María ; Núñez Álvarez, Nuria Ofelia ; Anguita, J. V. ; Vicent López, José Luis | American Institute of Physics | 2007-08-06Superconducting Nb films have been grown on top of arrays of Cu nanotriangles. These asymmetric pinning centers strongly modify the vortex lattice dynamics. Two rectification effects have been observed: (i) longitudinal ratchet effect when the i[...]texto impreso
Rollano, V. ; Muñoz Noval, Álvaro ; Valle, J. del ; Menghini, M. ; Ory, M. C. de ; Prieto, J. L. ; Navarro Palma, Elena ; González Herrera, Elvira María ; Vicent López, José Luis | IOP Publishing Ltd. | 2019-11-29A controlled local enhancement of superconductivity yields unexpected modifications in the vortex dynamics. This local enhancement has been achieved by designing an array of superconducting Nb nanostructures embedded in a V superconducting film.[...]texto impreso
Villegas, J. E. ; González Herrera, Elvira María ; Montero, M. I. ; Schuller, Ivan K. ; Vicent López, José Luis | American Physical Society | 2005-08We have studied vortex-lattice dynamics as a function of driving force direction, in superconducting Nb films with periodic pinning arrays of magnetic dots. Square and rectangular symmetry arrays define channels that guide the vortex-lattice mot[...]texto impreso
Sefrioui, Zouhair ; Arias Serna, Diego ; González Herrera, Elvira María ; León Yebra, Carlos ; Santamaría Sánchez-Barriga, Jacobo ; Vicent López, José Luis | American Physical Society | 2001-01-18Epitaxial YBa_(2)Cu_(3)O_(7) thin films, grown by high-pressure dc sputtering, are irradiated with He^(+) ions at 80 keV with doses between 10^(14) and 10^(15) cm^(-2). Irradiation reduces the critical temperature but it does not modify the carr[...]texto impreso
Sefrioui, Zouhair ; Arias, D. ; González Herrera, Elvira María ; León, C. ; Santamaría Sánchez-Barriga, Jacobo ; Vicent López, José Luis | American Physical Society | 2001-02-01Epitaxial YBa_2Cu_3O_7 thin films, grown by high-pressure de sputtering, an irradiated with He^(+) ions at 80 keV with doses between 10_(14) and 10_(15) cm^(-2). Irradiation reduces the critical temperature but it does not modify the carrier con[...]texto impreso
Puig, T. ; Galante, F. ; González Herrera, Elvira María ; Vicent López, José Luis ; Martínez, B. ; Obradors, X. | American Physical Society | 1999-11-01The angular dependence of the in-plane resistivity ?(T,H, ?) of melt textured YBa_2Cu_3O_7/Y_2BaCuO_5 composites has been measured in a large range of magnetic fields and temperatures and from them, the intrinsic anisotropy of the superconductin[...]texto impreso
González Herrera, Elvira María ; Anguita, J. V. ; Villegas, J. E. ; Vicent López, José Luis | Elsevier Science BV | 2003-05Ordered arrays of submicrometric Ni lines have been fabricated in sputtered Nb films. Magnetotransport R(H) and (I, V) curves were measured close to the critical temperature using a cross-shape bridge that allows us to apply current in two direc[...]texto impreso
Villegas, J. E. ; González Herrera, Elvira María ; Sefrioui, Z. ; Santamaría Sánchez-Barriga, Jacobo ; Vicent López, José Luis | American Physical Society | 2005-11Magnetotransport properties have been used to investigate vortex phases in Nb films with periodic arrays of magnetic pinning centers. This kind of samples show a continuous glass transition similar to that observed in Nb plain films, but the per[...]texto impreso
Gómez, A. ; Valle Granda, Javier del ; González Herrera, Elvira María ; Chiliotte, C. E. ; Carreira, S. J. ; Bekeris, V. ; Prieto, J. L. ; Schuller, Ivan K. ; Vicent López, José Luis | IOP publishing ltd | 2014Hybrid magnetic arrays embedded in superconducting films are ideal systems to study the competition between different physical (such as the coherence length) and structural length scales such as are available in artificially produced structures.[...]texto impreso
Pérez de Lara, D. ; Alija, A. ; González Herrera, Elvira María ; Vélez, M. ; Martín, J. I. ; Vicent López, José Luis | American Physical Society | 2010-11-03Arrays of Ni nanodots embedded in Nb superconducting films have been fabricated by sputtering and electron-beam lithography techniques. The arrays are periodic triangular lattices of circular Ni dots arranged in a kagomélike pattern with broken [...]texto impreso
Pérez de Lara, David ; Erekhinsky, M. ; González Herrera, Elvira María ; Rosen, Y. J. ; Schuller, Ivan K. ; Vicent López, José Luis | American Physical Society | 2011-05-09Triangular arrays of Ni nanotriangles embedded in superconducting Nb films exhibit unexpected dynamical vortex effects. Collective pinning with a vortex-lattice configuration different from the expected fundamental triangular "Abrikosov state" i[...]texto impreso
Sefrioui, Zouhair ; Arias Serna, Diego ; León Yebra, Carlos ; Santamaría Sánchez-Barriga, Jacobo ; González Herrera, Elvira María ; Vicent López, José Luis ; Prieto, P. | American Physical Society | 2004-08-09We investigate the zero-magnetic-field dynamic scaling in Bi_(2)Sr_(2)CaCu_(2)O_(8) thin films from nonlinear currentvoltage sI-Vd characteristics and by using the concavity criterion recently proposed by Strachan et al. [Phys. Rev. Lett. 87, 06[...]texto impreso
Sefrioui, Z. ; Arias, D. ; León, C. ; Santamaría Sánchez-Barriga, Jacobo ; González Herrera, Elvira María ; Vicent López, José Luis | American Physical Society | 2004-08We investigate the zero-magnetic-field dynamic scaling in Bi_2Sr_2CaCu_2O_8 thin films from nonlinear current-voltage (I-V) characteristics and by using the concavity criterion recently proposed by Strachan [Phys. Rev. Lett. 87, 067007 (2001)] .[...]