9,061 research outputs found
Fate of the inert three-flavor, spin-zero color-superconducting phases
I investigate some of the inert phases in three-flavor, spin-zero
color-superconducting quark matter: the CFL phase (the analogue of the B phase
in superfluid ), the A and A* phases, and the 2SC and sSC phases. I
compute the pressure of these phases with and without the neutrality condition.
It is shown that the 2SC phase is identical to the A* phase up to a color
rotation. The CFL phase is the energetically favored phase except for a small
region of intermediate densities where the 2SC/A* phase is favored.Comment: 9 pages, 1 figure; the version accepted to publish in PR
Binary fluid amplifier solves stability and load problems
Digital fluid amplifier has load intensity, high stability, and operates at low reynolds numbers. It contains specially designed nozzles to provide uniform exit-velocity profiles and to ensure jets of low turbulence
The genomes and history of domestic animals
This paper reviews how mammalian genomes are utilized in modern genetics for the detection of genes and polymorphisms (mutations) within domesticated animal (mostly livestock) genomes that are related to traits of economic importance to humans. Examples are given of how genetic analysis allows to determine key genes associated with the quality and quantity of milk in cattle and key genes for meat production. Various questions are reviewed, such as how contemporary methods of genome sequencing allow to maximise the effective detection of coding and regulatory DNA polymorphisms within the genomes of major domesticated mammals (cattle, sheep and pigs) and the history of their formation from the standpoint of genetics
Pairing of a trapped resonantly-interacting fermion mixture with unequal spin populations
We consider the phase separation of a trapped atomic mixture of fermions with
unequal spin populations near a Feshbach resonance. In particular, we determine
the density profile of the two spin states and compare with the recent
experiments of Partridge et al. (cond-mat/0511752). Overall we find quite good
agreement. We identify the remaining discrepancies and pose them as open
problems.Comment: 4 figures, 4+ pages, revtex
The ground state in a spin-one color superconductor
Color superconductors in which quarks of the same flavor form Cooper pairs
are investigated. These Cooper pairs carry total spin one. A systematic
group-theoretical classification of possible phases in a spin-one color
superconductor is presented, revealing parallels and differences to the theory
of superfluid He. General expressions for the gap parameter, the critical
temperature, and the pressure are derived and evaluated for several spin-one
phases, with special emphasis on the angular structure of the gap equation. It
is shown that the (transverse) color-spin-locked phase is expected to be the
ground state.Comment: 36 pages, 3 figures, error corrected in App. C, conclusion change
A constrained random-force model for weakly bending semiflexible polymers
The random-force (Larkin) model of a directed elastic string subject to
quenched random forces in the transverse directions has been a paradigm in the
statistical physics of disordered systems. In this brief note, we investigate a
modified version of the above model where the total transverse force along the
polymer contour and the related total torque, in each realization of disorder,
vanish. We discuss the merits of adding these constraints and show that they
leave the qualitative behavior in the strong stretching regime unchanged, but
they reduce the effects of the random force by significant numerical
prefactors. We also show that a transverse random force effectively makes the
filament softer to compression by inducing undulations. We calculate the
related linear compression coefficient in both the usual and the constrained
random force model.Comment: 4 pages, 1 figure, accepted for publication in PR
Long-range order in the A-like phase of superfluid 3He in aerogel
A mutual action of the random anisotropy brought in the superfluid 3He by
aerogel and of the global anisotropy caused by its deformation is considered.
Strong global anisotropy tends to suppress fluctuations of orientation of the
order parameter and stabilizes ABM order parameter. In a limit of vanishing
anisotropy these fluctuations are getting critical. It is argued that still in
a region of small fluctuations the average order parameter can acquire "robust"
component. This component maintains a long-range order even in a limit of
vanishing global anisotropy.Comment: A contribution to QFS 2007 in Kazan, revised for publication in the
Proceeding
Vortex Viscosity in Magnetic Superconductors Due to Radiation of Spin Waves
In type-II superconductors that contain a lattice of magnetic moments,
vortices polarize the magnetic system inducing additional contributions to the
vortex mass, vortex viscosity, and vortex-vortex interaction. Extra magnetic
viscosity is caused by radiation of spin waves by a moving vortex. Like in the
case of Cherenkov radiation, this effect has a characteristic threshold
behavior and the resulting vortex viscosity may be comparable to the well-known
Bardeen-Stephen contribution. The threshold behavior leads to an anomaly in the
current-voltage characteristics, and a drop in dissipation for a current
interval that is determined by the magnetic excitation spectrum.Comment: 4 pages, 1 figur
The Trapped Polarized Fermi Gas at Unitarity
We consider population-imbalanced two-component Fermi gases under external
harmonic confinement interacting through short-range two-body potentials with
diverging s-wave scattering length. Using the fixed-node diffusion Monte Carlo
method, the energies of the "normal state" are determined as functions of the
population-imbalance and the number of particles. The energies of the trapped
system follow, to a good approximation, a universal curve even for fairly small
systems. A simple parameterization of the universal curve is presented and
related to the equation of state of the bulk system.Comment: 4 pages, 2 tables, 2 figure
Induced superfluidity of imbalanced Fermi gases near unitarity
The induced intraspecies interactions among the majority species, mediated by
the minority species, is computed for a population-imbalanced two-component
Fermi gas. Although the Feshbach-resonance mediated interspecies interaction is
dominant for equal populations, leading to singlet s-wave pairing, we find that
in the strongly imbalanced regime the induced intraspecies interaction leads to
p-wave pairing and superfluidity of the majority species. Thus, we predict that
the observed spin-polaron Fermi liquid state in this regime is unstable to
p-wave superfluidity, in accordance with the results of Kohn and Luttinger,
below a temperature that, near unitarity, we find to be within current
experimental capabilities. Possible experimental signatures of the p-wave state
using radio-frequency spectroscopy as well as density-density correlations
after free expansion are presented.Comment: 15 pages, 13 figures, submitted to Phys. Rev.
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