Symmetry and Z_2-Orbifolding Approach in Five-dimensional Lattice Gauge Theory

In a lattice gauge-Higgs unification scenario using a Z_2-orbifolded extra-dimension, we find a new global symmetry in a case of SU(2) bulk gauge symmetry. It is a global symmetry on sites in a fixed point with respect to Z_2-orbifolding, independent of the bulk gauge symmetry. It is shown that the vacuum expectation value of a Z_2-projected Polyakov loop is a good order parameter of the new symmetry. The effective theory on lattice is also discussed.Comment: 13 pages, 3 figures; refined the explanation

4f-shell configuration of Yb in InP studied by electron spin resonance

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Electron spin resonance of Er–oxygen complexes in GaAs grown by metal organic chemical vapor deposition

We have performed electron spin resonance (ESR) measurements on Er-doped GaAs grown with oxygen codoping by metal organic chemical vapor deposition. An isotropic line (an effective g value, g = 5.95) which had been already reported was observed in samples without oxygen codoping. On the other hand, for samples with oxygen codoping other strong anisotropic ESR lines originated from four kinds of Er3 + (4f11) centers (A, B, C, and D) were newly observed in addition to the weaker isotropic line. The anisotropic g tensors obtained by analyzing the angular dependence of the ESR lines indicate that B and C centers are of orthorhombic C2v symmetry, A center has lower symmetry than orthorhombic symmetry, and D center is of trigonal C3i symmetry. The ESR intensities of A, B, and C centers were approximately two orders of magnitude higher than that of the isotropic line with g = 5.95. The ESR intensity of D center was one order of magnitude lower than those of A, B, and C. The Er concentration dependence of the relative ESR intensities of these centers was investigated, which indicates (i) the ESR intensities of A and D increase with increasing Er concentration, and (ii) those of B and C are saturated above the Er concentration [Er] >= 1018 cm – 3. The ESR measurement under light illumination, as well as the Er concentration dependence, suggests that the B center with C2v symmetry corresponds to the dominant Er luminescent center under host photoexcitation

An experimental and theoretical study into the facile, homogenous (N-Heterocyclic Carbene)2-Pd(0) catalyzed diboration of internal and terminal alkynes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Pd(ITMe)(2)(PhC CPh) acts as a highly reactive pre-catalyst in the unprecedented homogenous catalyzed diboration of terminal and internal alkynes, yielding a number of novel and known syn-1,2-diborylalkenes in a 100% stereoselective manner. DFT calculations suggest that a similar reaction pathway to that proposed for platinum phosphine analogues is followed, and that destabilization of key intermediates by the NHCs is vital to the overall success for the palladium-catalyzed B-B addition to alkynes.62074617467EPSRC Standard Research Student (DTG) [EP/L505109/1]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [2013/04813-6, 2015/11840-5, 2015/01491-3]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Vortex Lattice Structures of a Bose-Einstein Condensate in a Rotating Lattice Potential

We study vortex lattice structures of a trapped Bose-Einstein condensate in a rotating lattice potential by numerically solving the time-dependent Gross-Pitaevskii equation. By rotating the lattice potential, we observe the transition from the Abrikosov vortex lattice to the pinned lattice. We investigate the transition of the vortex lattice structure by changing conditions such as angular velocity, intensity, and lattice constant of the rotating lattice potential.Comment: 6 pages, 8 figures, submitted to Quantum Fluids and Solids Conference (QFS 2006