Frequency and power dependence of spin-current emission by spin pumping in a thin film YIG/Pt system

This paper presents the frequency dependence of the spin current emission in a hybrid ferrimagnetic insulator/normal metal system. The system is based on a ferrimagnetic insulating thin film of Yttrium Iron Garnet (YIG, 200 nm) grown by liquid-phase-epitaxy (LPE) coupled with a normal metal with a strong spin-orbit coupling (Pt, 15 nm). The YIG layer presents an isotropic behaviour of the magnetization in the plane, a small linewidth, and a roughness lower than 0.4 nm. Here we discuss how the voltage signal from the spin current detector depends on the frequency [0.6 - 7 GHz], the microwave power, Pin, [1 - 70 mW], and the in-plane static magnetic field. A strong enhancement of the spin current emission is observed at low frequencies, showing the appearance of non-linear phenomena.Comment: 7 pages, 5 figure

Volar Perilunate Dislocation: A Case Report and Review of the Literature

Perilunate dislocations, lunate dislocations and perilunate fracture dislocations are rare injuries comprising of less than 10% of all wrist injuries. Volar peri-lunate dislocations (VPLDs) account for less than 3% of perilunate dislocations. These severe carpal injuries occur after high-energy trauma to the wrist and falls on the outstretched hand. We present a case of a missed VPLD who developed parasthesia in the distribution of the median nerve 18 months after the initial injury. A plain film radiograph revealed a stage II VPLD. Nerve conduction studies confirmed compression of the median nerve at the carpal tunnel. VPLDs are extremely rare injuries. A quarter of perilunate dislocations are missed on initial presentation. The outcome is poor for missed injuries and this patient is aware that a wrist fusion may be required in the future for to treat symptoms

Criteria for accurate determination of the magnon relaxation length from the nonlocal spin Seebeck effect

The nonlocal transport of thermally generated magnons not only unveils the underlying mechanism of the spin Seebeck effect, but also allows for the extraction of the magnon relaxation length ($\lambda_m$) in a magnetic material, the average distance over which thermal magnons can propagate. In this study, we experimentally explore in yttrium iron garnet (YIG)/platinum systems much further ranges compared with previous investigations. We observe that the nonlocal SSE signals at long distances ($d$) clearly deviate from a typical exponential decay. Instead, they can be dominated by the nonlocal generation of magnon accumulation as a result of the temperature gradient present away from the heater, and decay geometrically as $1/d^2$. We emphasize the importance of looking only into the exponential regime (i.e., the intermediate distance regime) to extract $\lambda_m$. With this principle, we study $\lambda_m$ as a function of temperature in two YIG films which are 2.7 and 50 $\mu$m in thickness, respectively. We find $\lambda_m$ to be around 15 $\mu$m at room temperature and it increases to 40 $\mu$m at $T=$ 3.5 K. Finite element modeling results agree with experimental studies qualitatively, showing also a geometrical decay beyond the exponential regime. Based on both experimental and modeling results we put forward a general guideline for extracting $\lambda_m$ from the nonlocal spin Seebeck effect.Comment: 9 pages, 7 figure

Observation of the spin Peltier effect

We report the observation of the spin Peltier effect (SPE) in the ferrimagnetic insulator Yttrium Iron Garnet (YIG), i.e. a heat current generated by a spin current flowing through a Platinum (Pt)|YIG interface. The effect can be explained by the spin torque that transforms the spin current in the Pt into a magnon current in the YIG. Via magnon-phonon interactions the magnetic fluctuations modulate the phonon temperature that is detected by a thermopile close to the interface. By finite-element modelling we verify the reciprocity between the spin Peltier and spin Seebeck effect. The observed strong coupling between thermal magnons and phonons in YIG is attractive for nanoscale cooling techniques.Comment: 5 pages, 3 figures, 4 pages supplementary information, 4 supplementary figure

Magnetic resonance spectroscopy of perpendicularly magnetized permalloy multilayer disks

Using a Magnetic Resonance Force Microscope, we compare the ferromagnetic resonance spectra of individual micron-size disks with identical diameter, 1 $m$m, but different layer structures. For a disk composed of a single 43.3 nm thick permalloy (Py) layer, the lowest energy mode in the perpendicular configuration is the uniform precession. The higher energy modes are standing spin-waves confined along the diameter of the disk. For a Cu(30)/Py(100)/Cu(30) nm multilayer structure, it has been interpreted that the lowest energy mode becomes a precession localized at the Cu/Py interfaces. When the multilayer is changed to Py(100)/Cu(10)/Py(10) nm, this localized mode of the thick layer is coupled to the precession of the thin layer

Anesthesie topique par oxybuprocaine dans la chirurgie de cataracte: à propos de 100 cas

L'anesthésie topique lors de la chirurgie de la cataracte par phacoemulsification est devenue le meilleur choix pour les ophtalmologistes, Nous rapportons les résultats d'une étude prospective incluant 100 cas de cataractes simples opérées sous anesthésie topique par Oxybuprocaïne 0.4%, l'objectif est d'évaluer les avantages et les inconvénients, l'efficacité et la tolérance de ce protocole dans la chirurgie de cataracte par phacoemulsification. Étude prospective portant sur 100 patients opérés pour cataracte simple stade I, II et III sous anesthésie topique par instillation de quatre gouttes d'Oxybuprocaïne 0.4% collyre, nous avons analysé les complications rencontrées et le confort des patients à l'aide de l'échelle visuelle analogique. La tolérance du patient durant l'acte chirurgical est excellente ainsisur échelle visuelle analogique(EVA) de la douleur était de au alentour de 1 dans la majorité des cas (87 cas/ 92) soit (94% des cas). Ce protocole d'anesthésie topique permet l'éviction de toutes les complications liées aux anesthésies péribulbaire, latérobulbaire ou sous ténonienne et les risques de toxicité endothéliale par injection d'anesthésique intracamérulaire et semble apporter une efficacité anesthésique suffisante, une excellente tolérance. Dans 92% des cas, une anesthésie topique de surface par Oxybuprocaïne 0.4% collyre apparaît suffisante pour une chirurgie de cataracte simple

Bayesian Probabilities and the Histories Algebra

We attempt a justification of a generalisation of the consistent histories programme using a notion of probability that is valid for all complete sets of history propositions. This consists of introducing Cox's axioms of probability theory and showing that our candidate notion of probability obeys them. We also give a generalisation of Bayes' theorem and comment upon how Bayesianism should be useful for the quantum gravity/cosmology programmes.Comment: 10 pages, accepted by Int. J. Theo. Phys. Feb 200

Variabilité génétique du nombre de cellules épidermiques de l’hypocotyle dans l’embryon et identification des QTL contrôlant ce caractère chez la Légumineuse modèle Medicago truncatula

National audienc

Green network protocols and algorithms

Lloret, J.; Ghafoor, KZ.; Rawat, DB.; Nasser, Y. (2015). Green network protocols and algorithms. Journal of Network and Computer Applications. 58:192-193. https://doi.org/10.1016/j.jnca.2015.11.004S1921935