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Related papers: Low-frequency and shot noises in CoFeB/MgO/CoFeB m…

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We measured the shot noise in the CoFeB/MgO/CoFeB-based magnetic tunneling junctions with a high tunneling magnetoresistance ratio (over 200% at 3 K). Although the Fano factor in the anti-parallel configuration is close to unity, it is…

We report on the low frequency (LF) noise measurements in magnetic tunnel junctions (MTJs) below 4 K and at low bias, where the transport is strongly affected by scattering with magnons emitted by hot tunnelling electrons, as thermal…

Mesoscale and Nanoscale Physics · Physics 2015-01-06 Liang Liu , Li Xiang , Huiqiang Guo , Jian Wei , D. L. Li , Z. H. Yuan , J. F. Feng , X. F. Han , J. M. D. Coey

We report on room temperature low frequency noise due to magnetic inhomogeneities/domain walls (MI/DWs) in elliptic submicron FeCoB/MgO/FeCoB magnetic tunnel junctions with an area between 0.0245 and 0.0675{\mu}m2. In the smaller area…

Mesoscale and Nanoscale Physics · Physics 2012-04-18 D. Herranz , A. Gomez-Ibarlucea , M. Schäfers , A. Lara , G. Reiss , F. G. Aliev

We demonstrate that shot noise in Fe/MgO/Fe/MgO/Fe double-barrier magnetic tunnel junctions is determined by the relative magnetic configuration of the junction and also by the asymmetry of the barriers. The proposed theoretical model,…

Mesoscale and Nanoscale Physics · Physics 2012-09-21 J. P. Cascales , D. Herranz , F. G. Aliev , T. Szczepanski , V. K. Dugaev , J. Barnas , A. Duluard , M. Hehn , C. Tiusan

We report that low frequency (up to 200 kHz) noise spectra of magnetic tunnel junctions with areas ~10^{-10}cm^2$ at 10 Kelvin deviate significantly from the typical 1/f behavior found in large area junctions at room temperature. In most…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 B. Zhong , Y. Chen , S. Garzon , T. M. Crawford , R. A. Webb

We analyze shot noise in a magnetic tunnel junction with a two-level quantum dot attached to the magnetic electrodes. The considerations are limited to the case when some transport channels are suppressed at low temperatures. Coupling of…

Mesoscale and Nanoscale Physics · Physics 2017-01-10 T. Szczepanski , V. K. Dugaev , J. Barnas , I. Martinez , J. P. Cascales , J. -Y. Hong , M. -T. Lin , F. G. Aliev

Low temperature (10K) high voltage bias dynamic conductivity (up to 2.7V) and shot noise (up to 1V) were studied in epitaxial Fe(100)/Fe-C/MgO(100)/Fe(100) magnetic tunnel junctions, as a function of the magnetic state. The junctions show…

Mesoscale and Nanoscale Physics · Physics 2008-02-26 R. Guerrero , D. Herranz , F. G. Aliev , F. Greullet , C. Tiusan , M. Hehn , F. Montaigne

We develop a semiclassical Boltzmann-Langevin theory of the spin polarized shot noise in a diffusive normal metal spin-valve connected by tunnel contacts to ferromagnetic reservoirs with noncollinear magnetizations. We obtain basic…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 B. Abdollahipour , M. Zareyan

We compute the shot noise in ballistic and disordered Fe/MgO/Fe tunnel junctions by a wave function-matching method. For tunnel barriers with no more than 5 atomic layers we find a suppression of the Fano factor as a function of the…

Materials Science · Physics 2015-06-03 Kai Liu , Ke Xia , Gerrit E. W. Bauer

We measured the shot noise in fully epitaxial Fe/MgAl2OX/Fe-based magnetic tunneling junctions (MTJs). While the Fano factor to characterize the shot noise is very close to unity in the antiparallel configuration, it is reduced to 0.98 in…

Frequency dependent current noise in ferromagnetic double junctions with Coulomb blockade is studied theoretically in the limit of sequential tunneling. Two different relaxation processes are found in the correlations between spin polarized…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 B. R. Bulka , J. Martinek , G. Michalek , J. Barnas

We present a detailed study of the spin-torque diode effect in CoFeB/MgO/CoFe/NiFe magnetic tunnel junctions. From the evolution of the resonance frequency with magnetic field at different angles, we clearly identify the free-layer mode and…

We report the experimental observation of sub-Poissonian shot noise in single magnetic tunnel junctions, indicating the importance of tunneling via impurity levels inside the tunnel barrier. For junctions with weak zero-bias anomaly in…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 R. Guerrero , F. G. Aliev , Y. Tserkovnyak , T. S. Santos , J. S. Moodera

When current flows through a magnetic tunnel junction (MTJ), there is spin accumulation at the electrode-barrier interfaces if the magnetic moments of the two ferromagnetic electrodes are not aligned. Here we report that such nonequilibrium…

Mesoscale and Nanoscale Physics · Physics 2016-05-11 Liang Liu , Jiasen Niu , Huiqiang Guo , Jian Wei , D. L. Li , J. F. Feng , X. F. Han , J. M. D. Coey , X. -G. Zhang

We have performed a systematic analysis of the low frequency 1/f-noise in single grain boundary junctions in the colossal magnetoresistance material La_{2/3}Ca_{1/3}MnO_{3-delta}. The grain boundary junctions were formed in epitaxial…

Strongly Correlated Electrons · Physics 2009-11-07 J. B. Philipp , L. Alff , A. Marx , R. Gross

We report on room temperature magnetoresistance and low frequency noise in sub-100nm elliptic CoFeB/MgO/CoFeB magnetic tunnel junctions with ultrathin (0.9nm) barriers. For magnetic fields applied along the hard axis, we observe current…

Mesoscale and Nanoscale Physics · Physics 2013-05-28 J. P. Cascales , D. Herranz , J. L. Sambricio , U. Ebels , J. A. Katine , F. G. Aliev

Fluctuations of electric current in a spin valve consisting of a diffusive conductor connected to ferromagnetic leads and operated in the giant magnetoresistance regime are studied. It is shown that a new source of fluctuations due to…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 E. G. Mishchenko

Spin-dependent transport through a multilevel quantum dot weakly coupled to ferromagnetic leads is analyzed theoretically by means of the real-time diagrammatic technique. Both the sequential and cotunneling processes are taken into…

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

We study shot noise and cross correlations in a four terminal spin-valve geometry using a Boltzmann-Langevin approach. The Fano factor (shot noise to current ratio) depends on the magnetic configuration of the leads and the spin-flip…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 W. Belzig , M. Zareyan

We report on room temperature 1/f noise in fully epitaxial Fe(45nm)/MgO(2.6nm)/Fe(10nm) magnetic tunnel junctions (MTJs) with and without carbon doping of the Fe/MgO bottom interface. We have found that the normalized noise (Hooge factor)…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 F. G. Aliev , R. Guerrero , D. Herranz , R. Villar , F. Greullet , C. Tiusan , M. Hehn
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