All metal objects support fluctuating currents that are responsible for evanescent-wave Johnson noise in their vicinity due to both thermal and quantum effects. The fields can decohere qubits. It is quantified by the average value of $\mathbf{B}(\mathbit{x},t)\phantom{\rule{0.28em}{0ex}}\mathbf{B}({\mathbit{x}}^{\ensuremath{'}},{t}^{\ensuremath{'}})$ its time Fourier transform. We develop forma...

We compare bridge voltage response measurements to ac magnetic fields from a giant magnetoresistive sensor with noise measurements on the same sensor. The small-signal response (for applied ac magnetic fields between 0.1 mOe rms and 30 mOe) is much less than is the slope of a dc voltage versus field curve, because of hysteretic effects. Noise statistics are used to estimate the size and number ...

We report on the recording performances and signal-to-noise ratio analyses of perpendicular magnetic bit-patterned media. Two different types of magnetic samples are investigated. They differ by the way that they were patterned (nano-imprint versus e-beam lithography) as well as their magnetic properties (Co/Pt multilayers and CoCrPt alloy are the recording layers). By using a contact read/writ...

We consider the effect of a random magnetic field in the convective zone of the Sun on resonant neutrino spin-flavour oscillations. The expected signals in the different experiments (SK,GALLEX-SAGE,Homestake) are obtained as a function of the level of noise, regular magnetic field and neutrino mixing parameters. Previous results obtained for small mixing and ad-hoc regular magnetic profiles are...

We have studied low-frequency noise in the normal and mixed states of high-Tc thin films. In the normal state, resistance fluctuations with a 1/f power spectrum are observed from 100 K up to 300 K. The normal state noise is largely attributable to hopping or reordering of oxygen vacancies which in turn lead to fluctuations in local carrier density in the copper oxygen planes. Analysis shows a s...

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, based on sequential tunneling through the system and including spin relaxation, successfully accounts for the experimental observations for bias voltages below 0...

Human body heat emission and others external causes can interfere in magnetic resonance image acquisition and produce noise. In this kind of images, the noise, when no signal is present, is Rayleigh distributed and its wavelet coefficients can be approximately modeled by a Gaussian distribution. Noiseless magnetic resonance images can be modeled by a Laplacian distribution in the wavelet domain...

N. Locatelli, A. Mizrahi, A. Accioly, R. Matsumoto, A. Fukushima, H. Kubota, S. Yuasa, V. Cros, L. G. Pereira, D. Querlioz, J.-V. Kim, and J. Grollier Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, Campus de l’Ecole Polytechnique, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France Institut d’Electronique Fondamentale, UMR CNRS 8622, Université Paris-Sud, 91405 Ors...

Maxwell pressure is the cause of stator deflection at the origin of acoustic noise radiated by stator. That is why precise determination of air-gap radial flux density Bg is of prime importance. It could be obtained by finite element method, semi numerical or totally analytic method with computation of magneto motive force and permeance. Slot number, pole pair number and PWM affecting acoustic ...