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Related papers: Spin-polarized tunneling in ferromagnetic double b…

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We study spin dependent phonomena in superconducting junctions in both ballistic and diffusive regimes. For ballistic junctions we study both ferromagnet / $s$- and d-wave superconductor junctions and two dimensional electron gas / s-wave…

Superconductivity · Physics 2009-11-11 T. Yokoyama , Y. Tanaka

We study spin polarization in a split-gate quantum wire focussing on the effect of a realistic smooth potential due to remote donors. Electron interaction and spin effects are included within the density functional theory in the local spin…

Mesoscale and Nanoscale Physics · Physics 2008-04-04 M. Evaldsson , S. Ihnatsenka , I. V. Zozoulenko

We have measured the tunnelling current in Nb/Nb$_x$O$_y$/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…

Superconductivity · Physics 2009-11-13 E. M. González , A. D. Folgueras , R. Escudero , J. Ferrer , F. Guinea , J. L. Vicent

We report measurements of magnetic switching and steady-state magnetic precession driven by spin-polarized currents in nanoscale magnetic tunnel junctions with low-resistance, < 5 Ohm-micron-squared, barriers. The current densities required…

We have measured and modeled, using three different approaches, the tunneling current in a Nb/NbxOy/Ni planar tunnel junction. The experimental data could be fitted and the correct current polarization could be extracted using a simple…

We study spin and charge currents pumped by precessing magnetization of a single ferromagnetic layer within F|I|N or F|I|F (F-ferromagnet; I-insulator; N-normal-metal) multilayers of nanoscale thickness attached to two normal metal…

Mesoscale and Nanoscale Physics · Physics 2009-04-16 Son-Hsien Chen , Ching-Ray Chang , John Q. Xiao , Branislav K. Nikolic

We demonstrate electrical electron spin injection via interband tunneling in ferromagnetic/nonmagnetic semiconductor Esaki diodes. An interband tunnel junction between ferromagnetic p+-(Ga,Mn)As and nonmagnetic n+-GaAs under reverse-bias…

Materials Science · Physics 2007-05-23 Makoto Kohda , Yuzo Ohno , Koji Takamura , Fumihiro Matsukura , Hideo Ohno

We propose two new approaches for regulating spin polarization and spin inversion in a conducting junction within a tight-binding framework based on wave-guide theory. The system comprises a magnetic quantum ring with finite modulation in…

Mesoscale and Nanoscale Physics · Physics 2018-09-19 Moumita Patra , Santanu K. Maiti

We study theoretically the spin-dependent transport in ferromagnet/normal-metal/ferromagnet double tunnel junctions by special attention to cotunneling in the Coulomb blockade region. The spin accumulation caused by cotunneling squeezes the…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Hiroshi Imamura , Saburo Takahashi , Sadamichi Maekawa

Quantitative understanding of the relationship between quantum tunneling and Fermi surface spin polarization is key to device design using topological insulator surface states. By using spin-resolved photoemission spectroscopy with…

We report on spin injection experiments at a Co/Al$_2$O$_3$/GaAs interface with electrical detection. The application of a transverse magnetic field induces a large voltage drop $\Delta V$ at the interface as high as 1.2mV for a current…

Materials Science · Physics 2011-10-05 M. Tran , H. Jaffres , C. Deranlot , J. -M. George , A. Fert , A. Miard , A. Lemaitre

Magnetic tunnel junctions with a ferrimagnetic barrier layer have been studied to understand the role of the barrier layer in the tunneling process - a factor that has been largely overlooked until recently. Epitaxial oxide junctions of…

Strongly Correlated Electrons · Physics 2008-09-26 B. B. Nelson-Cheeseman , R. V. Chopdekar , L. M. B. Alldredge , J. S. Bettinger , E. Arenholz , Y. Suzuki

The occurrence of inhomogeneous spin-density distribution in multilayered ferromagnetic diluted magnetic semiconductor nanostructures leads to strong dependence of the spin-polarized transport properties on these systems. The spin-dependent…

A theory of spin-polarized electron transport in ferromagnet/semiconductor heterostructures, based on a unified semiclassical description of ballistic and diffusive transport in semiconductor structures, is developed. The aim is to provide…

Materials Science · Physics 2009-11-11 R. Lipperheide , U. Wille

Double layer two-dimensional electron systems at high perpendicular magnetic field are used to realize magnetic tunnel junctions in which the electrons at the Fermi level in the two layers have either parallel or anti-parallel spin…

Mesoscale and Nanoscale Physics · Physics 2017-05-10 J. P. Eisenstein , L. N. Pfeiffer , K. W. West

We describe a new means for electrically creating spin polarization in semiconductors. In contrast to spin injection of electrons by tunneling through a reverse-biased Schottky barrier, we observe spin accumulation at the…

Materials Science · Physics 2009-11-10 J. Stephens , J. Berezovsky , J. P. McGuire , L. J. Sham , A. C. Gossard , D. D. Awschalom

We consider spin-dependent tunneling through a gallium arsenide barrier, a material which has no inversion symmetry. We are dealing with free electrons, with one effective mass and a spin-splitting in the barrier material. When we take into…

Mesoscale and Nanoscale Physics · Physics 2009-09-29 T. L. Hoai Nguyen , Henri-Jean Drouhin , Jean-Eric Wegrowe , Guy Fishman

The electron tunneling in half metallic manganite tunnel junctions is studied by using a quantum mechanically treated double exchange model. We show that the stimulation of spin excitations, caused by the strong Hund's coupling between the…

Condensed Matter · Physics 2009-11-07 R. Y. Gu , L. Sheng , C. S. Ting

An important consequence of the discovery of giant magnetoresistance in metallic magnetic multilayers is a broad interest in spin dependent effects in electronic transport through magnetic nanostructures. An example of such systems are…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 J. Barnas , I. Weymann

We study spin and charge diffusion in metallic-ferromagnet/topological-insulator junctions. The coupled diffusion equations are derived perturbatively with respect to the strength of the interlayer tunneling. We calculate spin accumulation…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 Takehito Yokoyama , Yaroslav Tserkovnyak