Single-shot time-resolved measurements of nanosecond-scale spin-transfer induced switching: stochastic versus deterministic aspects

Using high bandwidth resistance measurements, we study the single-shot response of tunnel junctions subjected to spin torque pulses. After the pulse onset, the switching proceeds by a ns-scale incubation delay during which the resistance is quiet, followed by a 400 ps transition terminated by a large ringing that is damped progressively. While the incubation delay fluctuates significantly, the resistance traces are reproducible once this delay is passed. After switching, the time-resolved resistance traces indicate micromagnetic configurations that are rather spatially coherent.     

Stability characteristics of transition layer solutions

The multiple existences and their stability properties of stationary solutions with a single transition layer in some scalar reaction-diffusion equation are shown. Each solution is constructed by using classical singular perturbation methods and its stability property is determined by a simple algebraic quantity, say index, appearing in the construction of a solution.     

T in a model of a nonlinear optical resonator

Oscillations characterized by three incommensurate frequencies (three-dimensional torus of T³) appear in a model of a nonlinear optical resonator driven by a laser beam with transversally inhomogeneous identity distribution. Destruction of T³ leading to chaos occurs when a combination harmonic of two frequencies grows suddenly in the vicinity of the third frequency (and vice versa).     

A description of decoupled bands using the angular momentum projection method applied to the coherent phonon state

The decoupled bands of the odd-A La-isotopes are described by the angular momentum projection method. The coherent phonon state is assumed for the intrinsic wave function of the core. The present model covers the particle-vibrator and the particle-rotor coupling model. The results are in good agreement with the experimental energy spectra.     

The adsorption of SO2 on iron surfaces studied by x-ray photoelectron spectroscopy

The interaction of SO₂ with evaporated iron surfaces in the temperature range 80–450 K was investigated by using X-ray photoelectron spectroscopy. At 300 K, SO₂ decomposed at the initial stage of the interaction and gave adsorbed S with the S2p peak at 161.9 eV and adsorbed O with the O1s at 530.0 eV. Further exposure of SO₂ gave adsorbed SO₄ with S2p at 166.8 eV O1s at 531.3 eV, being different in binding energies from ionic SO₄^2?. This indicates the two stage reaction Of SO₂ with iron surface; SO₂(gas) → S(ads) + 20(ads), SO₂(gas) + 2O(ads) → SO₄(ads). The first reaction did not occur at low temperature or in the presence of adsorbed O. The adsorbed SO₄ formed at 80 K showed a quantitative decomposition reaction into S(ads) and O(ads) in the temperature range 200–350 K.