10,682 research outputs found
Nonlinear conduction of sliding electronic crystals: Charge and Spin Density Waves
A model of local metastable states due to the pinning induces plastic
deformations allows to describe the nonlinear I-V curves in sliding density
waves -DW. With increasing the DW velocity v, the metastable states of
decreasing lifetimes ~1/v are accessed. The characteristic second threshold
field is reached when configurations of shortest life time are accessed by the
fast moving DW. Thus the DW works as a kind of a ``linear accelerator'' testing
virtual states.Comment: To be published in Proceedings of ECRYS-99, J. de Physique, Coll.,
December 1999, http://ipnweb.in2p3.fr/~lptms/membres/brazov
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
Level statistics inside the vortex of a superconductor and symplectic random matrix theory in an external source
In the core of the vortex of a superconductor, energy levels appear inside
the gap. We discuss here through a random matrix approach how these levels are
broadened by impurities. It is first shown that the level statistics is
governed by an ensemble consisting of a symplectic random potential added to a
non-random matrix. A generalization of previous work on the unitary ensemble in
the presence of an external source (which relied on the Itzykson-Zuber
integral) is discussed for this symplectic case through the formalism
introduced by Harish-Chandra and Duistermaat-Heckman. This leads to explicit
formulae for the density of states and for the correlation functions, which
describe the cross-over from the clean to the dirty limits.Comment: 34 pages, Revte
Localization and Interaction Effects in Strongly Underdoped La2-xSrxCuO4
The in-plane magnetoresistance (MR) in La2-xSrxCuO4 films with 0.03 < x <
0.05 has been studied in the temperature range 1.6 K to 100 K, and in magnetic
fields up to 14 T, parallel and perpendicular to the CuO2 planes. The behavior
of the MR is consistent with a predominant influence of interaction effects at
high temperatures, switching gradually to a regime dominated by spin scattering
at low T. Weak localization effects are absent. A positive orbital MR appears
close to the boundary between the antiferromagnetic and the spin-glass phase,
suggesting the onset of Maki-Thompson superconducting fluctuations deep inside
the insulating phase.Comment: 4 pages, 3 figures, to appear in Phys. Rev. Letter
On the ground state of gapless two flavor color superconductors
This paper is devoted to the study of some aspects of the instability of two
flavor color superconductive quark matter. We find that, beside color
condensates, the Goldstone boson related to the breaking of suffers of
a velocity instability. We relate this wrong sign problem, which implies the
existence of a Goldstone current in the ground state or of gluonic
condensation, to the negative squared Meissner mass of the gluon in
the g2SC phase. Moreover we investigate the Meissner masses of the gluons and
the squared velocity of the Goldstone in the multiple plane wave LOFF states,
arguing that in such phases both the chromo-magnetic instability and the
velocity instability are most probably removed. We also do not expect Higgs
instability in such multiple plane wave LOFF. The true vacuum of gapless two
flavor superconductors is thus expected to be a multiple plane wave LOFF state.Comment: 16 pages, RevTe3X4 styl
Phase Separation in Bose-Fermi-Fermi Mixtures as a Probe of Fermi Superfluidity
We study the phase diagram of a mixture of Bose-Einstein condensate and a
two-component Fermi gas. In particular, we identify the regime where the
homogeneous system becomes unstable against phase separation. We show that,
under proper conditions, the phase separation phenomenon can be exploited as a
robust probe of Fermi superfluid
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