Rashba Spin Interferometer

A spin interferometer utilizing the Rashba effect is proposed. The novel design is composed of a one-dimensional (1D) straight wire and a 1D half-ring. By calculating the norm of the superposed wave function, we derive analytical expressions to describe the spin interference spectrum as a function of the Rashba coupling strength. Presented spin interference results are identified to include (i) the quantum-mechanical 4pi rotation effect, (ii) geometric effect, and (iii) Shubnikov-de Haas-like beating effect.Comment: 3 pages, 3 figures, appears in the proceedings of the 10th Joint MMM/Intermag Conferenc

Quantum World-line Monte Carlo Method with Non-binary Loops and Its Application

A quantum world-line Monte Carlo method for high-symmetrical quantum models is proposed. Firstly, based on a representation of a partition function using the Matsubara formula, the principle of quantum world-line Monte Carlo methods is briefly outlined and a new algorithm using non-binary loops is given for quantum models with high symmetry as SU(N). The algorithm is called non-binary loop algorithm because of non-binary loop updatings. Secondary, one example of our numerical studies using the non-binary loop updating is shown. It is the problem of the ground state of two-dimensional SU(N) anti-ferromagnets. Our numerical study confirms that the ground state in the small N <= 4 case is a magnetic ordered Neel state, but the one in the large N >= 5 case has no magnetic order, and it becomes a dimer state.Comment: 14 pages, 5 figures, Invited talk at the 18th Annual Workshop on Recent Developments of Computer Simulation Studies in Condensed Matter Physics, Athens, 7-11 March, 200

Evaluation of axial load-bearing capacity of concrete columns strengthened by a new section enlargement method

The objective of this study is to evaluate the axial load-bearing capacity of section-enlargement concrete columns. To reach the objection, a new strengthened method in which columns are jacketed with a large welded octagonal stirrup at the center and four spiral stirrups at the corners of column is developed. The new section-enlargement method avoids interrupting existing columns and improves the reliability of strengthened part, besides, the confining stress generated by octagonal stirrup and spiral stirrups enhances the compressive strength and deformability of strengthened columns. In addition, sixteen large-scale concrete columns strengthened by the new strengthened method were tested under axial compressive loads. The experimental results show that the axial compression ratio of existing column generates stressstrain lag in strengthened part and decreases the load-bearing capacity of specimens; the stirrups in strengthened part significantly enhance the axial load-bearing capacity of specimens. According to confinement conditions, the cross-section of specimens is divided into five parts and the confinement factor for each part is calculated to establish the prediction models for the load-bearing capacity of specimens. Furthermore, by comparing the results between the developed model and existing models, the developed model has high accuracy in evaluating the load-bearing capacity of strengthened columns. First published online 20 December 202