133 research outputs found
Probing the interface magnetism in the FeMn/NiFe exchange bias system using magnetic second harmonic generation
Second harmonic generation magneto-optic Kerr effect (SHMOKE) experiments,
sensitive to buried interfaces, were performed on a polycrystalline NiFe/FeMn
bilayer in which areas with different exchange bias fields were prepared using
5 KeV He ion irradiation. Both reversible and irreversible uncompensated spins
are found in the antiferromagnetic layer close to the interface with the
ferromagnetic layer. The SHMOKE hysteresis loop shows the same exchange bias
field as obtained from standard magnetometry. We demonstrate that the exchange
bias effect is controlled by pinned uncompensated spins in the
antiferromagnetic layer.Comment: submitted to Phys. Rev. Let
An exact solution method for 1D polynomial Schr\"odinger equations
Stationary 1D Schr\"odinger equations with polynomial potentials are reduced
to explicit countable closed systems of exact quantization conditions, which
are selfconsistent constraints upon the zeros of zeta-regularized spectral
determinants, complementing the usual asymptotic (Bohr--Sommerfeld)
constraints. (This reduction is currently completed under a certain vanishing
condition.) In particular, the symmetric quartic oscillators are admissible
systems, and the formalism is tested upon them. Enforcing the exact and
asymptotic constraints by suitable iterative schemes, we numerically observe
geometric convergence to the correct eigenvalues/functions in some test cases,
suggesting that the output of the reduction should define a contractive
fixed-point problem (at least in some vicinity of the pure case).Comment: flatex text.tex, 4 file
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