11,768 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
The preparation of crystalline lactic acid
On account of its importance in intermediary metabolism, lactic acid was among the first compounds chosen in our plan, which we have described in a previous communication (1), to augment the available data on the free energies of formation of substances significant in biological chemistry. It was necessary for this purpose to obtain pure crystalline lactic acid, free of water, anhydride, and lactide. The only description in the literature of the preparation of crystalline lactic acid is that of Krafft and Dÿes (2). Table I shows that the product obtained by their method contains relatively large quantities of anhydro impurities. The subject of the present communication is the description of a method which yields the active isomers of lactic acid in a crystalline state, free of water, anhydride, and lactide, supplemented by the description of two methods of separating the active forms from the commercial syrup (1). Lactic acid commercially available at present either is in the form of the U.S.P. syrup, which usually exhibits a low optical activity corresponding to the excess it happens to contain, which is variable, of one or the other optical isomer, or is the expensive zinc sarcolactate. The methods described below now make it possible to obtain easily and quickly and at low cost large quantities of both active isomers in a relatively high degree of purity
Fermi liquid features of the one-dimensional Luttinger liquid
We show that the one-dimensional (1D) electron systems can also be described
by Landau's phenomenological Fermi-liquid theory. Most of the known results
derived from the Luttinger-liquid theory can be retrieved from the 1D
Fermi-liquid theory.
Exact correspondence between the Landau parameters and Haldane parameters is
established. The exponents of the dynamical correlation functions and the
impurity problem are also discussed based on the finite size corrections of
elementary excitations with the predictions of the conformal field theory,
which provides a bridge between the 1D Fermi-liquid and the Luttinger liquid.Comment: RevTeX, 5 pages, published versio
Hartree-Fock-Bogoliubov Theory of Dipolar Fermi Gases
We construct a fully self-consistent Hartree-Fock-Bogoliubov theory that
describes a spinless Fermi gas with long-range interaction. We apply this
theory to a system of uniform dipolar fermionic polar molecules, which has
attracted much attention recently, due to rapid experimental progress in
achieving such systems. By calculating the anisotropic superfluid order
parameter, and the critical temperature , we show that, "hign "
superfluid can be achieved with a quite modest value of interaction strength
for polar molecules. In addition, we also show that the presence of the Fock
exchange interaction enhances superfluid pairing.Comment: 4.1 pages, 4 figure
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