11,806 research outputs found
SL(2,C) Chern-Simons theory and the asymptotic behavior of the colored Jones polynomial
We clarify and refine the relation between the asymptotic behavior of the
colored Jones polynomial and Chern-Simons gauge theory with complex gauge group
SL(2,C). The precise comparison requires a careful understanding of some
delicate issues, such as normalization of the colored Jones polynomial and the
choice of polarization in Chern-Simons theory. Addressing these issues allows
us to go beyond the volume conjecture and to verify some predictions for the
behavior of the subleading terms in the asymptotic expansion of the colored
Jones polynomial.Comment: 15 pages, 7 figure
SU(2) Non-Abelian Holonomy and Dissipationless Spin Current in Semiconductors
Following our previous work [S. Murakami, N. Nagaosa, S. C. Zhang, Science
301, 1348 (2003)] on the dissipationless quantum spin current, we present an
exact quantum mechanical calculation of this novel effect based on the linear
response theory and the Kubo formula. We show that it is possibxle to define an
exactly conserved spin current, even in the presence of the spin-orbit coupling
in the Luttinger Hamiltonian of p-type semiconductors. The light- and the
heavy-hole bands form two Kramers doublets, and an SU(2) non-abelian gauge
field acts naturally on each of the doublets. This quantum holonomy gives rise
to a monopole structure in momentum space, whose curvature tensor directly
leads to the novel dissipationless spin Hall effect, i.e., a transverse spin
current is generated by an electric field. The result obtained in the current
work gives a quantum correction to the spin current obtained in the previous
semiclassical approximation.Comment: 14 pages, 2 figures, added some discussions, to appear in Phys. Rev.
The nucleoside analog GS-441524 strongly inhibits feline infectious peritonitis (FIP) virus in tissue culture and experimental cat infection studies.
Feline infectious peritonitis (FIP) is a common and highly lethal coronavirus disease of domestic cats. Recent studies of diseases caused by several RNA viruses in people and other species indicate that antiviral therapy may be effective against FIP in cats. The small molecule nucleoside analog GS-441524 is a molecular precursor to a pharmacologically active nucleoside triphosphate molecule. These analogs act as an alternative substrate and RNA-chain terminator of viral RNA dependent RNA polymerase. We determined that GS-441524 was non-toxic in feline cells at concentrations as high as 100 uM and effectively inhibited FIPV replication in cultured CRFK cells and in naturally infected feline peritoneal macrophages at concentrations as low as 1 uM. We determined the pharmacokinetics of GS-441524 in cats in vivo and established a dosage that would sustain effective blood levels for 24 h. In an experimental FIPV infection of cats, GS-441524 treatment caused a rapid reversal of disease signs and return to normality with as little as two weeks of treatment in 10/10 cats and with no apparent toxicity
Spin-orbit lateral superlattices: energy bands and spin polarization in 2DEG
The Bloch spinors, energy spectrum and spin density in energy bands are
studied for the two-dimensional electron gas (2DEG) with Rashba spin-orbit (SO)
interaction subject to one-dimensional (1D) periodic electrostatic potential of
a lateral superlattice. The space symmetry of the Bloch spinors with spin
parity is studied. It is shown that the Bloch spinors at fixed quasimomentum
describe the standing spin waves with the wavelength equal to the superlattice
period. The spin projections in these states have the components both parallel
and transverse to the 2DEG plane. The anticrossing of the energy dispersion
curves due to the interplay between the SO and periodic terms is observed,
leading to the spin flip. The relation between the spin parity and the
interband optical selection rules is discussed, and the effect of magnetization
of the SO superlattice in the presence of external electric field is predicted.Comment: 6 pages, 5 figures, reported at the International Conferences
"Nanophysics and Nanoelectronics" (Nizhny Novgorod, Russia, March 2006) and
"Nanostructures: Physics and Technology" (St Petersburg, Russia, June 2006
Phase transition between the quantum spin Hall and insulator phases in 3D: emergence of a topological gapless phase
Phase transitions between the quantum spin Hall and the insulator phases in
three dimensions are studied. We find that in inversion-asymmetric systems
there appears a gapless phase between the quantum spin Hall and insulator
phases in three dimensions, which is in contrast with the two-dimensional case.
Existence of this gapless phase stems from a topological nature of gapless
points (diabolical points) in three dimensions, but not in two dimensions.Comment: 16 pages, 5 figure
Antiferro-quadrupole Ordering of CeB Studied by Resonant X-ray Scattering
Under zero magnetic field, a quadrupolar order parameter at q_Q=(1/2,1/2,1/2)
in a typical antiferro-quadrupole (AFQ) ordering compound CeB6 has been
observed for the first time by means of a resonant X-ray scattering (RXS) te\
chnique. The RXS is observed at the 2p->5d dipole transition energy of the Ce
L3-edge. Using this RXS technique to observe the pure order parameter of the
AFQ state, the magnetic phase diagram of Phase II is first determined.Comment: 7 pages, 4 figure
Vertex operators for quantum groups and application to integrable systems
Starting with any R-matrix with spectral parameter, obeying the Yang-Baxter
equation and a unitarity condition, we construct the corresponding infinite
dimensional quantum group U_{R} in term of a deformed oscillators algebra A_R.
The realization we present is an infinite series, very similar to a vertex
operator.
Then, considering the integrable hierarchy naturally associated to A_{R}, we
show that U_{R} provides its integrals of motion. The construction can be
applied to any infinite dimensional quantum group, e.g. Yangians or elliptic
quantum groups.
Taking as an example the R-matrix of Y(N), the Yangian based on gl(N), we
recover by this construction the nonlinear Schrodinger equation and its Y(N)
symmetry.Comment: 19 pages, no figure, Latex2e Error in theorem 3.3 and lemma 3.1
correcte
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