We study theoretically the lattice instability in the spin gap systems under magnetic eld. With the magnetic eld larger than a critical value h c1 , the spin gap is collapsed and the magnetization arises. We found that the lattice distortion occurs in the spin-ladder at an incommensurate wavevector corresponding to the magnetization, while it does not occur in the Haldane system. At low tempera...

Magnetic anisotropy and magnetization reversal phenomena are studied in Ga12xMnxAs films grown on GaAs~001!. From the azimuthal dependence of the magneto-optical Kerr rotation and magnetic linear dichroism, the in-plane ^100& directions are unambiguously assigned as axes of easy magnetization. The values of the cubic and uniaxial anisotropies are determined. Magnetization reversal proceeds by n...

Fig. 3 Dependence of magnetization ratios between control (Mc) and saturation (Ms) on the rate constants (kf=0-0.4 s) and repetition time (tr=0.25-30 s) simulated by the Bloch-equations. Flip angle (β=45°) and d2=0 were applied for the simulations. The magnetization ratios indicated by circle, solid and blank squares were measured with tr = 12, 3 and 1s, respectively. An Improved Magnetization ...

We report a patient with biopsy-proven progressive multifocal leukoencephalopathy (PML) who was serially imaged with MRI and magnetization transfer imaging. The magnetization transfer ratio (MTR) was profoundly and significantly diminished when compared with normal control subjects. The pattern of MTR was distinct from that of MS and periventricular ischemic white matter disease. Magnetization ...

in this paper, we study the electronic properties of a concentric triple quantum ring using exact diagonalization technique. the energy spectra and magnetization for a single electron and two electrons, in the presence of an applied magnetic field, are calculated and discussed. it is shown that, for two-interacting electrons, the period of aharonov-bohm oscillations decreases to the half of tha...

Bergmann et al. [Phys. Rev. B 77, 054414 (2008)] present an analytical theory explaining the behavior of ferromagnetic cobalt nanowires with perpendicular anisotropy. This theory, which predicts a sinusoidal variation of the magnetization along the long axis of the wire, depends upon an assumption that "the magnetization is constant within a cross section of the wire." In this Comment we use mi...

This thesis presents optical characterizations of interfaces in ferromagnetic heterostructures and thin films used for spin polarized electronic devices. In these experiments, femtosecond laser spectroscopies are exploited to investigate the interface magnetization reversal, spin precession, and band offset, which are crucial in determining the performances of spintronic devices. First, magneti...

We study transition matrices for projected dynamics in the energy-magnetization, magnetization, and energy spaces. Several single-spin-flip dynamics are considered, such as the Glauber and Metropolis canonical ensemble dynamics, and the Metropolis dynamics for three multicanonical ensembles: the flat energy-magnetization, the flat energy, and the flat magnetization histograms. From the numerica...