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108 results on '"Isasa M"'

2. Absence of magnetic proximity effects in magnetoresistive Pt/CoFe2O4 hybrid interfaces

Author

Valvidares, M., Dix, N., Isasa, M., Ollefs, K., Wilhelm, F., Rogalev, A., Sánchez, F., Pellegrin, E., Bedoya-Pinto, A., Gargiani, P., Hueso, L. E., Casanova, F., and Fontcuberta, J.

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Ultra-thin Pt films grown on insulating ferrimagnetic CoFe2O4 (111) epitaxial films display a magnetoresistance upon rotating the magnetization of the magnetic layer. We report here X-ray magnetic circular dichroism (XMCD) recorded at Pt-L2,3 and Pt-M3 edges. The results indicate that the Pt magnetic moment, if any, is below the detection limit (< 0.001 {\mu}$_B$/Pt), thus strongly favoring the view that the presence of CoFe2O4 does not induce the formation of magnetic moments in Pt. Therefore, the observed magnetoresistance cannot be attributed to some sort of proximity-induced magnetic moments at Pt ions and subsequent magnetic-field dependent scattering. It thus follows that either bulk (spin Hall and Inverse spin Hall Effects) or interface (Rashba) spin-orbit related effects dominate the observed magnetoresistance. Furthermore, comparison of bulk magnetization and XMCD data at (Fe,Co)-L2,3 edges suggests the presence of some spin disorder in the CoFe2O4 layer which may be relevant for the observed anomalous non-saturating field-dependence of spin Hall magnetoresistance., Comment: 14 pages, 5 figures PDF of revised manuscript as finally accepted for publication in Phys. Rev. B

Published
2015
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3. Simultaneous detection of the spin-Hall magnetoresistance and the spin-Seebeck effect in Platinum and Tantalum on Yttrium Iron Garnet

Author

Vlietstra, N., Isasa, M., Shan, J., Youssef, J. Ben, Casanova, F., and van Wees, B. J.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

The spin-Seebeck effect (SSE) in platinum (Pt) and tantalum (Ta) on yttrium iron garnet (YIG) has been investigated by both externally heating the sample (using an on-chip Pt heater on top of the device) as well as by current-induced heating. For SSE measurements, external heating is the most common method to obtain clear signals. Here we show that also by current-induced heating it is possible to directly observe the SSE, separate from the also present spin-Hall magnetoresistance (SMR) signal, by using a lock-in detection technique. Using this measurement technique, the presence of additional 2nd order signals at low applied magnetic fields and high heating currents is revealed. These signals are caused by current-induced magnetic fields (Oersted fields) generated by the used AC-current, resulting in dynamic SMR signals., Comment: 9 pages, 6 figures

Published
2014
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4. Origin of inverse Rashba-Edelstein effect at Cu/Bi interface using lateral spin valves

Author

Isasa, M., Martínez-Velarte, M. C., Villamor, E., Magén, C., Morellón, L., De Teresa, J. M., Ibarra, M. R., Vignale, G., Chulkov, E. V., Krasovskii, E. E., Hueso, L. E., and Casanova, F.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

The spin transport and spin-to-charge current conversion properties of bismuth are investigated using permalloy/copper/bismuth (Py/Cu/Bi)lateral spin valve structures. The spin current is strongly absorbed at the surface of Bi, leading to ultra-short spin diffusion lengths. A spin-to-charge current conversion is measured, which is attributed to the inverse Rashba-Edelstein effect at the Cu/Bi interface. The spin-current-induced charge current is found to change direction with increasing temperature. A theoretical analysis relates this behavior to the complex spin structure and dispersion of the surface states at the Fermi energy. The understanding of this phenomenon opens novel possibilities to exploit spin-orbit coupling to create, manipulate, and detect spin currents in 2D systems., Comment: 10 pages, 4 figures for the main text + 6 pages, 6 figures for the supplementary information

Published
2014
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6. CFT7455: A NOVEL, IKZF1/3 DEGRADER THAT DEMONSTRATES POTENT TUMOR REGRESSION IN A SPECTRUM OF NHL XENOGRAFT MODELS

Author

Perino, S, primary, Class, B, additional, Henderson, C, additional, Isasa, M, additional, Kirby, R. J, additional, Agafonov, R. V, additional, Chaturvedi, P, additional, Eron, S. J, additional, Good, A, additional, Hart, A. A, additional, Henderson, J. A, additional, Kreger, B. T, additional, Mahler, M, additional, Pollock, R. M, additional, Crystal, A. S, additional, Nasveschuk, C. G, additional, Fisher, S. L, additional, and Proia, D. A, additional

Published
2021
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9. Statistics of the degree of polarization

Author

del Rio, V. Santalla, Mosquera, J.M. Pidre, Isasa, M. Vera, and de Lorenzo, M.E.

Subjects
Antennas (Electronics) -- Research, Remote sensing -- Research, Business, Computers, Electronics, Electronics and electrical industries
Abstract

The degree of polarization of a wave, that depends on sensor and target parameters, provides information on the randomness of the scattering or emission from natural targets. It may be useful in the analysis and interpretation of remote sensing data. For that, precise statistical description of its estimate will be required. Probability density function, expected value and standard deviation of the maximum likelihood estimate of the degree of polarization are obtained assuming a complex Gaussian distribution of the field samples that appropriately describes radiometric data, and also, some radar data. Index Terms--Estimation, polarization.

Published
2006

10. Forest Fire Detection with Weather Radars

Author

del Rio, V. Santalla, primary, Nocelo-Lopez, R., additional, Vera-Isasa, M., additional, Garcia-Sanchez, M., additional, Cuinas, I., additional, Vazquez-Alejos, A., additional, Torio, P., additional, and de Lorenzo, E., additional

Published
2018
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13. Origin of inverse Rashba-Edelstein effect detected at the Cu/Bi interface using lateral spin valves

Author

Isasa, M., Martínez-Velarte, M.C., Villamor, E., Magén, C., Morellón, L., De Teresa, J.M., Ibarra, M.R., Vignale, G., Chulkov, E.V., Krasovskii, E.E., Hueso, L.E., and Casanova, F.

Subjects
Condensed Matter::Strongly Correlated Electrons
Abstract

The spin transport and spin-to-charge current conversion properties of bismuth are investigated using permalloy/copper/bismuth (Py/Cu/Bi) lateral spin valve structures. The spin current is strongly absorbed at the surface of Bi, leading to ultrashort spin-diffusion lengths. A spin-to-charge current conversion is measured, which is attributed to the inverse Rashba-Edelstein effect at the Cu/Bi interface. The spin-current-induced charge current is found to change direction with increasing temperature. A theoretical analysis relates this behavior to the complex spin structure and dispersion of the surface states at the Fermi energy. The understanding of this phenomenon opens novel possibilities to exploit spin-orbit coupling to create, manipulate, and detect spin currents in two-dimensional systems.

Published
2016

16. 3x3 Multibeam Network for a Triangular Array of Three Radiating Elements

Author

Garcia-Gasco Trujillo, Javier, Sierra Pérez, Manuel, Novo Garcia, A., and Vera Isasa, M.

Subjects
Telecomunicaciones, Astrophysics::Galaxy Astrophysics
Abstract

A multibeam antenna study based on Butler network will be undertaken in this document. These antenna designs combines phase shift systems with multibeam networks to optimize multiple channel systems. The system will work at 1.7 GHz with circular polarization. Specifically, result simulations and measurements of 3 element triangular subarray will be shown. A 45 element triangular array will be formed by the subarrays. Using triangular subarrays, side lobes and crossing points are reduced.

Published
2011

18. Análisis, diseño y realización de antenas planas ranuradas multisatélite

Author

Sierra Castañer, Manuel, Sierra Pérez, Manuel, Álvarez Fernández, Ángel, and Vera Isasa, M.

Subjects
Telecomunicaciones, Robótica e Informática Industrial, Computer Science::Information Theory
Abstract

A review of designs of linearly polarized parallel-plate slot antennas developed by the authors is presented. Different combinations are described: broadside beam, one and dual tilted-beam, one and dual polarized antennas. The antenna structure, the analysis methods and the feasibility of getting a dual beam and dual linearly polarized antenna with interesting characteristics and low cost are analyzed. Several designs are proposed and their features are studied. As a conclusion, it can be said that parallel- plate slot arrays are quite promising.

Published
2002

19. Diseño y construcción de antena plana de doble polarización basada en ranuras para recepción de TV por satélite

Author

Martínez Ollero, A., Sierra Castañer, Manuel, Sierra Pérez, Manuel, and Vera Isasa, M.

Subjects
Telecomunicaciones, Robótica e Informática Industrial
Abstract

In this paper we design and make a double-polarization plane slot antenna for Digital Television Satellite reception. The prototype will fulfil the DVB specifications and furthermore it should be simple to construct and cheap. Therefore in the design process and in the implementation process exists a compromise between the specifications, low costs and simplicity.

Published
2002

20. Antenas de ranuras en línea biplaca sin dieléctrico

Author

Álvarez Fernández, A., Vera Isasa, M., Sierra Castañer, Manuel, and Sierra Pérez, Manuel

Subjects
Telecomunicaciones, Robótica e Informática Industrial
Abstract

Antenas de Ranuras en Línea Biplaca sin Dieléctrico

Published
2002

21. Desarrollo de una antena plana de doble haz para televisión digital por satélite

Author

Izquierdo Manso, Joaquín, Sierra Pérez, Manuel, Sierra Castañer, Manuel, Vera Isasa, M., and Moreno Jiménez, Óscar

Subjects
Telecomunicaciones, Robótica e Informática Industrial, Astrophysics::Instrumentation and Methods for Astrophysics, Computer Science::Information Theory
Abstract

We show here the design of a dual beam linearly polarised flat antenna. The main goal is getting a low cost antenna to use for the simultaneous reception of Hispasat and Astra satellite emissions in the 12 GHz band. The gain needed for the antenna is around 30dBi. A rectangular array of slots in the upper side of a parallel plate wave guide form the main antenna structure. The guide is excited with two feeding structures from both sides of the antenna. This antenna has been analized with the TLM Method showed in [1]

Published
2000

22. Diseño de antena monopulso de polarización circular en guía radial

Author

Sierra Castañer, Manuel, Sierra Pérez, Manuel, Vera Isasa, M., and Fernández Jambrina, José Luis

Subjects
Telecomunicaciones, Robótica e Informática Industrial
Abstract

The authors propose the design of one radial line slot antenna with two simultaneous beams, one broadside beam and one conical beam. The antenna is a radial line slot antenna, with the slots placed on the upper plate in concentric rings. The radiation element is a slot pair, designed for getting left hand circular polarization. The antenna has been designed for working between 13.4 and 14 GHz. Both beams are obtained independently through very simple excitation circuits (Butler Networks). Comparing both radiation patterns, amplitude and phase, theta (0º to 10º) and phi (0º -360º) angles can be obtained.

Published
2000

24. Antena de ranuras sobre estructura biplaca rectangular

Author

Moreno Jiménez, Oscar, García Hidalgo, José Agustín, Sierra Castañer, Manuel, Sierra Pérez, Manuel, and Vera Isasa, M.

Subjects
Telecomunicaciones, Robótica e Informática Industrial
Abstract

Antena de Ranuras sobre Estructura Biplaca Rectangular

Published
1999

25. Diseño de antenas planas de ranuras con polarización lineal

Author

García Hidalgo, José Agustín, Sierra Castañer, Manuel, Sierra Pérez, Manuel, and Vera Isasa, M.

Subjects
Telecomunicaciones, Robótica e Informática Industrial
Abstract

Diseño de Antenas Planas de Ranuras con Polarización Lineal

Published
1998

30. Diseño de antenas en guía Radial ranurada

Author

Sierra Pérez, Manuel, Vera Isasa, M., and Sierra Castañer, Manuel

Subjects
Telecomunicaciones, Robótica e Informática Industrial
Abstract

Diseño de Antenas en Guía Radial Ranurada

Published
1995

46. Multiple-feed Coupling Measurements for Luneburg Lens Antenna.

Author

Franco-Vazquez, D., Vera-Isasa, M., and de Lorenzo Rodríguez, E.

Subjects
LENS antennas, ANTENNAS (Electronics), MICROWAVE lenses, BEAMFORMING, SIGNAL processing
Abstract

Mutual coupling measurements between two feeds of a Luneburg lens are presented in this paper. A 356 mm diameter Luneburg lens with two WR90 feeds is used to perform measurements within the 8-11 GHz frequency range. Results of mutual coupling with and without lens are presented for different spacing between the feeds for both vertical and horizontal polarization. Measurements with four feeds are also presented. [ABSTRACT FROM AUTHOR]

Published
2013

47. ENXENO: LEGO Robots from University Lab to K-12 Classroom.

Author

Alejos, A. Vazquez, Del Rio, V. Santalla, Isasa, M. Vera, De Lorenzo, E., Cuinas, I., and Sanchez, M. Garcia

Subjects
ROBOTS, PHYSICS laboratories, CLASSROOMS, TECHNOLOGICAL innovations, ELECTRICAL engineering, COMPUTER engineering
Abstract

Copyright of Electronics & Electrical Engineering is the property of Electronics & Electrical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2012

48. Fast analysis model for radial-line slot antennas.

Author

Sierra-Castanñer, M., Sierra-Pérez, M., Ver-Isasa, M., and Fernández-Jambrina, J. L.

Subjects
ANTENNAS (Electronics), MOMENTS method (Statistics), MAGNETIC coupling, ELECTRIC lines, ELECTRONIC equipment
Abstract

An analysis model of radial-line slot antennas (RLSAs) based on a simplified method of moments (MoM), with closed equations that represent the coupling inside the radial line and the coupling in the free space, was presented in [1]. In this paper, an improvement of that model, including both transmission-line equivalent circuits for slots on the upper plate of the radial line and an exciting probe inside the radial line is presented. This model is validated through measurements and simulations with full-wave analysis. Our goal is to obtain a tool fast enough to optimise this kind of antenna, which is composed of several probes and large number of slots. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 17–21, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20534 [ABSTRACT FROM AUTHOR]

Published
2005
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49. Multiprobe RLSA design for DBS reception.

Author

Sierra-Castañer, M., Sierra-Pérez, M., Vera-Isasa, M., and Fernández-Jambrina, J. L.

Subjects
ANTENNAS (Electronics), ANTENNA arrays, DIRECT broadcast satellite television, TELEVISION broadcasting, TELECOMMUNICATION satellites
Abstract

A synthesis method for circular-polarization radial-line slot antennas excited by four posts inside the radial line is presented. This excitation generates a rotational mode inside the waveguide, and the slots that radiate the field can be placed arranging concentric rings. The reflected field inside the radial line can be controlled. We present the design and a prototype model for this antenna that shows practical results. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 70–72, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10675 [ABSTRACT FROM AUTHOR]

Published
2003
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