6,377 research outputs found
Inert-states of spin-5 and spin-6 Bose-Einstein condensates
In this paper we consider spinor Bose-Einstein condensates with spin f=5 and
f=6 in the presence and absence of external magnetic field at the mean field
level. We calculate all of so-called inert-states of these systems.
Inert-states are very unique class of stationary states because they remain
stationary while Hamiltonian parameters change. Their existence comes from
Michel's theorem. For illustration of symmetry properties of the inert-states
we use method that allows classification of the systems as a polyhedron with 2f
vertices proposed by R. Barnett et al., Phys. Rev. Lett. 97, 180412 (2006).Comment: 19 pages, 4 figure
Thin Films of 3He -- Implications on the Identification of 3 He -A
Recently the identification of 3He-A with the axial state has been
questioned. It is suggested that the A-phase can actually be in the axiplanar
state. We point out in the present paper that experiments in a film geometry
may be useful to distinguish the above two possibilities. In particular a
second order phase transition between an axial and an axiplanar state would
occur as a function of thickness or temperature.Comment: 3 pages, no figures latex- revtex aps accepted by J. of Low
Temperature Physic
Josephson Current between Triplet and Singlet Superconductors
The Josephson effect between triplet and singlet superconductors is studied.
Josephson current can flow between triplet and singlet superconductors due to
the spin-orbit coupling in the spin-triplet superconductor but it is finite
only when triplet superconductor has , where and
are the perpendicular components of orbital angular momentum and spin angular
momentum of the triplet Cooper pairs, respectively. The recently observed
temperature and orientational dependence of the critical current through a
Josephson junction between UPt and Nb is investigated by considering a
non-unitary triplet state.Comment: 4 pages, no figure
Mechanisms of Spontaneous Current Generation in an Inhomogeneous d-Wave Superconductor
A boundary between two d-wave superconductors or an s-wave and a d-wave
superconductor generally breaks time-reversal symmetry and can generate
spontaneous currents due to proximity effect. On the other hand, surfaces and
interfaces in d-wave superconductors can produce localized current-carrying
states by supporting the T-breaking combination of dominant and subdominant
order parameters. We investigate spontaneous currents in the presence of both
mechanisms and show that at low temperature, counter-intuitively, the
subdominant coupling decreases the amplitude of the spontaneous current due to
proximity effect. Superscreening of spontaneous currents is demonstrated to be
present in any d-d (but not s-d) junction and surface with d+id' order
parameter symmetry. We show that this supercreening is the result of
contributions from the local magnetic moment of the condensate to the
spontaneous current.Comment: 4 pages, 5 figures, RevTe
Basic Properties of a Vortex in a Noncentrosymmetric Superconductor
We numerically study the vortex core structure in a noncentrosymmetric
superconductor such as CePt3Si without mirror symmetry about the xy plane.
A single vortex along the z axis and a mixed singlet-triplet Cooper pairing
model are considered.
The spatial profiles of the pair potential, local density of states,
supercurrent density, and radially-textured magnetic moment density around the
vortex are obtained in the clean limit on the basis of the quasiclassical
theory of superconductivity.Comment: 6 pages; submitted to Proc. of VORTEX I
Predictors of the Extent of Carotid Atherosclerosis in Patients Treated with Radiotherapy for Nasopharyngeal Carcinoma
published_or_final_versio
Dissipation of the 3^He A-B Transition
A rigorous hydrodynamic theory of the A-B transition is presented. All
dissipative processes are considered. At low interface velocities, those
occurring on hydrodynamic length scales, not considered hitherto, are most
probably the dominant ones.Comment: 13 pages, REVTeX, 2 figures, ITP-UH 13/9
Averaging approach to phase coherence of uncoupled limit-cycle oscillators receiving common random impulses
Populations of uncoupled limit-cycle oscillators receiving common random
impulses show various types of phase-coherent states, which are characterized
by the distribution of phase differences between pairs of oscillators. We
develop a theory to predict the stationary distribution of pairwise phase
difference from the phase response curve, which quantitatively encapsulates the
oscillator dynamics, via averaging of the Frobenius-Perron equation describing
the impulse-driven oscillators. The validity of our theory is confirmed by
direct numerical simulations using the FitzHugh-Nagumo neural oscillator
receiving common Poisson impulses as an example
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