20,499 research outputs found
The random field critical concentration in dilute antiferromagnets
Monte Carlo techniques are used to investigate the equilibrium threshold
concentration, xe, in the dilute anisotropic antiferromagnet Fe(x)Zn(1-x)F2 in
an applied magnetic field, considered to be an ideal random-field Ising model
system. Above xe equilibrium behavior is observed whereas below xe
metastability and domain formation dominate. Monte Carlo results agree very
well with experimental data obtained using this system.Comment: 9 pages, 3 figure
Two-component radiation model of the sonoluminescing bubble
Based on the experimental data from Weninger, Putterman & Barber, Phys. Rev.
(E), 54, R2205 (1996), we offer an alternative interpretation of their
experimetal results. A model of sonoluminescing bubble which proposes that the
electromagnetic radiation originates from two sources: the isotropic black body
or bramsstrahlung emitting core and dipole radiation-emitting shell of
accelerated electrons driven by the liquid-bubble interface is outlined.Comment: 5 pages Revtex, submitted to Phys. Rev.
Tridyne attitude control thruster investigation Final report
Experimental results of feasibility Tridyne attitude control thruste
Magnetic field-induced spectroscopy of forbidden optical transitions with application to lattice-based optical atomic clocks
We develop a method of spectroscopy that uses a weak static magnetic field to
enable direct optical excitation of forbidden electric-dipole transitions that
are otherwise prohibitively weak. The power of this scheme is demonstrated
using the important application of optical atomic clocks based on neutral atoms
confined to an optical lattice. The simple experimental implementation of this
method -- a single clock laser combined with a DC magnetic field-- relaxes
stringent requirements in current lattice-based clocks (e.g., magnetic field
shielding and light polarization), and could therefore expedite the realization
of the extraordinary performance level predicted for these clocks. We estimate
that a clock using alkaline earth-like atoms such as Yb could achieve a
fractional frequency uncertainty of well below 10^-17 for the metrologically
preferred even isotopes
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