Stripes, topological order, and deconfinement in a planar t-Jz model

We determine the quantum phase diagram of a two-dimensional bosonic t-Jz model as a function of the lattice anisotropy gamma, using a quantum Monte Carlo loop algorithm. We show analytically that the low-energy sectors of the bosonic and the fermionic t-Jz models become equivalent in the limit of small gamma. In this limit, the ground state represents a static stripe phase characterized by a non-zero value of a topological order parameter. This phase remains up to intermediate values of gamma, where there is a quantum phase transition to a phase-segregated state or a homogeneous superfluid with dynamic stripe fluctuations depending on the ratio Jz/t.Comment: 4 pages, 5 figures (2 in color). Final versio

Angular Momentum and Mutually Unbiased Bases

The Lie algebra of the group SU(2) is constructed from two deformed oscillator algebras for which the deformation parameter is a root of unity. This leads to an unusual quantization scheme, the {J2,Ur} scheme, an alternative to the familiar {J2,Jz} quantization scheme corresponding to common eigenvectors of the Casimir operator J2 and the Cartan operator Jz. A connection is established between the eigenvectors of the complete set of commuting operators {J2,Ur} and mutually unbiased bases in spaces of constant angular momentum.Comment: To be published in International Journal of Modern Physics

Limitations of Absolute Current Densities Derived from the Semel & Skumanich Method

Semel and Skumanich proposed a method to obtain the absolute electric current density, |Jz|, without disambiguation of 180 degree in the transverse field directions. The advantage of the method is that the uncertainty in the determination of the ambiguity in the magnetic azimuth is removed. Here, we investigate the limits of the calculation when applied to a numerical MHD model. We found that the combination of changes in the magnetic azimuth with vanishing horizontal field component leads to errors, where electric current densities are often strong. Where errors occur, the calculation gives |Jz| too small by factors typically 1.2 ~ 2.0.Comment: 10 pages, 4 figures. To appear on Science in China Series G: Physics, Mechanics & Astronomy, October 200

The uterine junctional zone: A 3-dimensional ultrasound study of patients with endometriosis

The uterine junctional zone (JZ) alterations are correlated with adenomyosis. An accurate evaluation of the JZ may be obtained by 3-dimensional transvaginal sonography (TVS). The aim of the present prospective study was to assess the value of detectable alterations by 3-dimensional TVS of the JZ in patients with pelvic endometriosis (diagnosed by laparoscopy and histologic condition) and to compare these findings with those of women without pelvic endometriosis