34,906 research outputs found
Novel vortex structures in dipolar condensates
We investigate the properties of single vortices and of vortex lattice in a
rotating dipolar condensate. We show that vortices in this system possess many
novel features induced by the long-range anisotropic dipolar interaction
between particles. For example, when the dipoles are polarized along the
rotation axis, vortices may display a crater-like structure; when dipoles are
polarized orthogonal to the rotation axis, vortex cores takes an elliptical
shape and the vortex lattice no longer possesses hexagonal symmetry.Comment: 4 pages, 5 figure
Exotic Topological States with Raman-Induced Spin-Orbit Coupling
We propose a simple experimental scheme to realize simultaneously the
one-dimensional spin-orbit coupling and the staggered spin-flip in ultracold
pseudospin- atomic Fermi gases trapped in square optical lattices. In the
absence of interspecies interactions, the system supports gapped Chern
insulators and gapless topological semimetal states. By turning on the -wave
interactions, a rich variety of gapped and gapless inhomogeneous topological
superfluids can emerge. In particular, a gapped topological Fulde-Ferrell
superfluid, in which the chiral edge states at opposite boundaries possess the
same chirality, is predicted.Comment: 11 pages, 6 figure
The Effects of Halo Assembly Bias on Self-Calibration in Galaxy Cluster Surveys
Self-calibration techniques for analyzing galaxy cluster counts utilize the
abundance and the clustering amplitude of dark matter halos. These properties
simultaneously constrain cosmological parameters and the cluster
observable-mass relation. It was recently discovered that the clustering
amplitude of halos depends not only on the halo mass, but also on various
secondary variables, such as the halo formation time and the concentration;
these dependences are collectively termed assembly bias. Applying modified
Fisher matrix formalism, we explore whether these secondary variables have a
significant impact on the study of dark energy properties using the
self-calibration technique in current (SDSS) and the near future (DES, SPT, and
LSST) cluster surveys. The impact of the secondary dependence is determined by
(1) the scatter in the observable-mass relation and (2) the correlation between
observable and secondary variables. We find that for optical surveys, the
secondary dependence does not significantly influence an SDSS-like survey;
however, it may affect a DES-like survey (given the high scatter currently
expected from optical clusters) and an LSST-like survey (even for low scatter
values and low correlations). For an SZ survey such as SPT, the impact of
secondary dependence is insignificant if the scatter is 20% or lower but can be
enhanced by the potential high scatter values introduced by a highly correlated
background. Accurate modeling of the assembly bias is necessary for cluster
self-calibration in the era of precision cosmology.Comment: 13 pages, 5 figures, replaced to match published versio
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