24,052 research outputs found
Hawking temperature from scattering off the charged 2D black hole
The charged 2D black hole is visualized as presenting an potential barrier
to on-coming tachyon wave. Since this takes the complicated
form, an approximate form is used for scattering analysis. We
calculate the reflection and transmission coefficients for scattering of
tachyon off the charged 2D black hole. The Hawking temperature is also derived
from the reflection coefficient by Bogoliubov transformation. In the limit of
, we recover the Hawking temperature of the 2D dilaton black hole.Comment: 12 pages 3 figures, RevTeX, to obtain figures contact author
([email protected]
Prediction of Giant Spin Motive Force due to Rashba Spin-Orbit Coupling
Magnetization dynamics in a ferromagnet can induce a spin-dependent electric
field through spin motive force. Spin current generated by the spin-dependent
electric field can in turn modify the magnetization dynamics through
spin-transfer torque. While this feedback effect is usually weak and thus
ignored, we predict that in Rashba spin-orbit coupling systems with large
Rashba parameter , the coupling generates the spin-dependent
electric field [\pm(\alpha_{\rm R}m_e/e\hbar) (\vhat{z}\times \partial
\vec{m}/\partial t)], which can be large enough to modify the magnetization
dynamics significantly. This effect should be relevant for device applications
based on ultrathin magnetic layers with strong Rashba spin-orbit coupling.Comment: 4+ pages, 2 figure
Propagating waves in an extremal black string
We investigate the black string in the context of the string theories. It is
shown that the graviton is the only propagating mode in the (2+1)--dimensional
extremal black string background. Both the dilation and axion turn out to be
non-propagating modes.Comment: Minor corrections, 11 pages in ReVTeX, no figure
Comment on ''the controlled charge ordering and evidence of the metallic state in PrCaMnO films''
In a recent paper (2000 \QTR{it}{J. Phys.: Condens. Matter} \QTR{bf}{12}
L133) Lee \QTR{it}{et al.} have studied the transport properties of
PrCaMnO thin films. They claimed that they are able to
controlled the charge-ordered (CO) state by the lattice strains. We propose
herein another alternative since another indexation of the orientation of the
film can be found leading to almost no distortion of the cell, as compared to
the bulk compound.Comment: 2 page
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