2,047 research outputs found
Rabi Oscillations in Landau-Quantized Graphene
We investigate the relation between the canonical model of quantum optics,
the Jaynes-Cummings Hamiltonian and Dirac fermions in quantizing magnetic
field. We demonstrate that Rabi oscillations are observable in the optical
response of graphene, providing us with a transparent picture about the
structure of optical transitions. While the longitudinal conductivity reveals
chaotic Rabi oscillations, the Hall component measures coherent ones. This
opens up the possibility of investigating a microscopic model of a few quantum
objects in a macroscopic experiment with tunable parameters.Comment: 5 pages, 4 figure
Trans-Magnetosonic Accretion in a Black Hole Magnetosphere
We present the critical conditions for hot trans-fast magnetohydrodynamical
(MHD) flows in a stationary and axisymmetric black-hole magnetosphere. To
accrete onto the black hole, the MHD flow injected from a plasma source with
low velocity must pass through the fast magnetosonic point after passing
through the ``inner'' or ``outer'' Alfven point. We find that a trans-fast MHD
accretion solution related to the inner Alfven point is invalid when the
hydrodynamical effects on the MHD flow dominate at the magnetosonic point,
while the other accretion solution related to the outer Alfven point is invalid
when the total angular momentum of the MHD flow is seriously large. When both
regimes of the accretion solutions are valid in the black hole magnetosphere,
we can expect the transition between the two regimes. The variety of these
solutions would be important in many highly energetic astrophysical situations.Comment: 27 pages, 12 figures, accepted to Ap
Statistical Analysis of Alumina/Metal Brazed Joints under Applying of Ultrasonic Waves(Materials, Metallurgy & Weldability)
Application of Ultrasonic Waves during Brazing of Alumina/Copper Using Zn-Sn Filler(Materials, Metallurgy & Weldability, INTERNATIONAL SYMPOSIUM OF JWRI 30TH ANNIVERSARY)
nature of the superdeformed band of and the evolution of the molecular structure
The relation between the superdeformed band of and molecular bands is studied by the deformed-base
antisymmetrized molecular dynamics with the Gogny D1S force. It is found that
the obtained superdeformed band members of have considerable
amount of the component. Above the superdeformed
band, we have obtained two excited rotational bands which have more prominent
character of the molecular band. These three
rotational bands are regarded as a series of
molecular bands which were predicted by using the unique
- optical potentil. As the excitation energy and principal
quantum number of the relative motion increase, the cluster structure becomes more prominent but at the same time, the band
members are fragmented into several states
Terbium-activated heavy scintillating glasses
Tb-activated scintillating glasses with high Ln2O3 (Ln=Gd, Y, Lu) concentration up to 40mol% have been prepared. The effects of Ln3+ ions on the density, thermal properties, transmission and luminescence properties under both UV and X-ray excitation have been investigated. The glasses containing Gd2O3 or Lu2O3 exhibit a high density of more than 6.0g/cm3. Energy transfer from Gd3+ to Tb3+ takes place in Gd-containing glass and as a result the Gd-containing glass shows a light yield 2.5 times higher than the Y-or Lu-containing glass. The Effect of the substitution of fluorine for oxygen on the optical properties was also investigated
Information Entropy in Cosmology
The effective evolution of an inhomogeneous cosmological model may be
described in terms of spatially averaged variables. We point out that in this
context, quite naturally, a measure arises which is identical to a fluid model
of the `Kullback-Leibler Relative Information Entropy', expressing the
distinguishability of the local inhomogeneous mass density field from its
spatial average on arbitrary compact domains. We discuss the time-evolution of
`effective information' and explore some implications. We conjecture that the
information content of the Universe -- measured by Relative Information Entropy
of a cosmological model containing dust matter -- is increasing.Comment: LateX, PRLstyle, 4 pages; to appear in PR
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