3,976 research outputs found
NMR relaxation rate in non-centrosymmetric superconductors
The spin-lattice relaxation rate of nuclear magnetic resonance in a clean
superconductor without inversion center is calculated for arbitrary pairing
symmetry and band structure, in the presence of strong spin-orbit coupling.Comment: 4 page
Calabi-Yau 3-folds from 2-folds
We consider type IIA string theory on a Calabi-Yau 2-fold with D6-branes
wrapping 2-cycles in the 2-fold. We find a complete set of conditions on the
supergravity solution for any given wrapped brane configuration in terms of
SU(2) structures. We reduce the problem of finding a supergravity solution for
the wrapped branes to finding a harmonic function on RCY. We then
lift this solution to 11-dimensions as a product of R and a
Calabi-Yau 3-fold. We show how the metric on the 3-fold is determined in terms
of the wrapped brane solution. We write down the distinguished (3,0) form and
the K{\"a}hler form of the 3-fold in terms of structures defined on the base
2-d complex manifold. We discuss the topology of the 3-fold in terms of the
D6-branes and the underlying 2-fold. We show that in addition to the
non-trivial cycles inherited from the underlying 2-fold there are new
2-cycles. We construct closed (1,1) forms corresponding to these new cycles. We
also display some explicit examples. One of our examples is that of D6-branes
wrapping the 2-cycle in an A ALE space, the resulting 3-fold has
, where is the number of D6-branes.Comment: 30 page
Spontaneous kidney rupture in polyarteritis nodosa presenting as an acute abdomen
CITATION: Edelstein, C. L. & Welke, H. 1991. Spontaneous kidney rupture in polyarteritis nodosa presenting as an acute abdome. South African Medical Journal, 79:52-53.The original publication is available at http://www.samj.org.zaAn acute abdomen in a patient with polyarteritis nodosa (PAN) is a perplexing and challenging problem for both the physician and the surgeon.Publisher’s versio
Signature of superconducting states in cubic crystal without inversion symmetry
The effects of absence of inversion symmetry on superconducting states are
investigated theoretically. In particular we focus on the noncentrosymmetric
compounds which have the cubic symmetry like LiPtB. An appropriate
and isotropic spin-orbital interaction is added in the Hamiltonian and it acts
like a magnetic monopole in the momentum space. The consequent pairing
wavefunction has an additional triplet component in the pseudospin space, and a
Zeeman magnetic field can induce a collinear supercurrent
with a coefficient . The effects of anisotropy embedded in the cubic
symmetry and the nodal superconducting gap function on are also
considered. From the macroscopic perspectives, the pair of mutually induced
and magnetization can affect the distribution of magnetic
field in such noncentrosymmetric superconductors, which is studied through
solving the Maxwell equation in the Meissner geometry as well as the case of a
single vortex line. In both cases, magnetic fields perpendicular to the
external ones emerge as a signature of the broken symmetry.Comment: 16 pages in pre-print forma
Training New Dental Health Providers in the U.S. (Full Report)
This 52 page report explores the interest and need to establish new midlevel dental providers in the U.S. The genesis of this interest is concern about access to care for underserved populations whose higher oral disease rates and unmet oral care needs are well documented. This document was published December 2009 and updated June 2010
On the spin susceptibility of noncentrosymmetric superconductors
We calculate the spin susceptibility of a superconductor without inversion
symmetry, both in the clean and disordered cases. The susceptibility has a
large residual value at zero temperature, which is further enhanced in the
presence of scalar impurities.Comment: 12 pages, 3 figure
Holography and Unquenched Quark-Gluon Plasmas
We employ the string/gauge theory correspondence to study properties of
strongly coupled quark-gluon plasmas in thermal gauge theories with a large
number of colors and flavors. In particular, we analyze non-critical string
duals of conformal (S)QCD, as well as ten dimensional wrapped fivebrane duals
of SQCD-like theories. We study general properties of the dual plasmas,
including the drag force exerted on a probe quark and the jet quenching
parameter. We find that these plasma observables depend on the number of colors
and flavors in the ``QCD dual''; in particular, we find that the jet quenching
parameter increases linearly with N_f/N_c at leading order in the probe limit.
In the ten dimensional case we find a non trivial drag coefficient but a
vanishing jet quenching parameter. We comment on the relation of this result
with total screening and argue that the same features are shared by all known
plasmas dual to fivebranes in ten dimensions. We also construct new D5 black
hole solutions with spherical horizon and show that they exhibit the same
features.Comment: 30 pages. v2: Comments in section 2 and references updated, a typo
fixe
Spontaneous kidney rupture in polyarteritis nodosa presenting as an acute abdomen
CITATION: Edelstein, C. L. & Welke, H. 1991. Spontaneous kidney rupture in polyarteritis nodosa presenting as an acute abdome. South African Medical Journal, 79:52-53.The original publication is available at http://www.samj.org.zaAn acute abdomen in a patient with polyarteritis nodosa (PAN) is a perplexing and challenging problem for both the physician and the surgeon.Publisher’s versio
Supersymmetric Electroweak Cosmic Strings
We study the connection between supersymmetry and a topological bound
in a two-Higgs-doublet system with an gauge group. We derive the Bogomol'nyi equations from
supersymmetry considerations showing that they hold provided certain conditions
on the coupling constants, which are a consequence of the huge symmetry of the
theory, are satisfied. Their solutions, which can be interpreted as electroweak
cosmic strings breaking one half of the supersymmetries of the theory, are
studied. Certain interesting limiting cases of our model which have recently
been considered in the literature are finally analyzed.Comment: 20 pages, RevTe
Magnetic properties of superconductors with strong spin-orbit coupling
We study the response of a superconductor with a strong spin-orbit coupling
on an external magnetic field. The Ginzburg-Landau free energy functional is
derived microscopically for a general crystal structure, both with and without
an inversion center, and for an arbitrary symmetry of the superconducting order
parameter. As a by-product, we obtain the general expressions for the intrinsic
magnetic moment of the Cooper pairs. It is shown that the Ginzburg-Landau
gradient energy in a superconductor lacking inversion symmetry has unusual
structure. The general formalism is illustrated using as an example CePtSi,
which is the first known heavy-fermion superconductor without an inversion
center.Comment: Published version, 14 pages, minor correction
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