Canonical Quantization of SU(3) Skyrme Model in a General Representation

A complete canonical quantization of the SU(3) Skyrme model performed in the collective coordinate formalism in general irreducible representations. In the case of SU(3) the model differs qualitatively in different representations. The Wess-Zumino-Witten term vanishes in all self-adjoint representations in the collective coordinate method for separation of space and time variables. The canonical quantization generates representation dependent quantum mass corrections, which can stabilize the soliton solution. The standard symmetry breaking mass term, which in general leads to representation mixing, degenerates to the SU(2) form in all self-adjoint representations.Comment: 24 RevTex4 pages, no figure

Spontaneous Z2 Symmetry Breaking in the Orbifold Daughter of N=1 Super Yang-Mills Theory, Fractional Domain Walls and Vacuum Structure

We discuss the fate of the Z2 symmetry and the vacuum structure in an SU(N)xSU(N) gauge theory with one bifundamental Dirac fermion. This theory can be obtained from SU(2N) supersymmetric Yang--Mills (SYM) theory by virtue of Z2 orbifolding. We analyze dynamics of domain walls and argue that the Z2 symmetry is spontaneously broken. Since unbroken Z2 is a necessary condition for nonperturbative planar equivalence we conclude that the orbifold daughter is nonperturbatively nonequivalent to its supersymmetric parent. En route, our investigation reveals the existence of fractional domain walls, similar to fractional D-branes of string theory on orbifolds. We conjecture on the fate of these domain walls in the true solution of the Z2-broken orbifold theory. We also comment on relation with nonsupersymmetric string theories and closed-string tachyon condensation.Comment: 37 pages, 7 figures. v2: various significant changes; revisions explained in the introduction. Final version to appear in Phys.Rev.

Infrared optical absorption spectra of CuO single crystals: Fermion-spinon band and dimensional crossover of the antiferromagnetic order

We have obtained mid-infrared optical absorption spectra of the S=1/2 quasi one-dimensional CuO using polarized transmission measurement and interpreted the spectra in terms of phonon assisted magnetic excitations. When the electric field is parallel to the main antiferromagnetic direction a Delta shaped peak is observed with the maximum at 0.23eV which is attributed to spinons along Cu-O chains. At low temperatures in the antiferromagnetic phase another peak appears at 0.16eV which is attributed to two-magnon absorption but the spinon peak remains. This behavior is interpreted as due to a dimensional crossover where the low temperature three-dimensional magnetic phase keeps short range characteristics of a one-dimensional magnet.Comment: 5 pages, 5 figure

High temperature superconductivity in dimer array systems

Superconductivity in the Hubbard model is studied on a series of lattices in which dimers are coupled in various types of arrays. Using fluctuation exchange method and solving the linearized Eliashberg equation, the transition temperature $T_c$ of these systems is estimated to be much higher than that of the Hubbard model on a simple square lattice, which is a model for the high $T_c$ cuprates. We conclude that these `dimer array' systems can generally exhibit superconductivity with very high $T_c$. Not only $d$-electron systems, but also $p$-electron systems may provide various stages for realizing the present mechanism.Comment: 4 pages, 9 figure

Magnetic Field-Induced Superconductor-Insulator-Metal Transition in an Organic Conductor: An Infrared Magneto-Optical Imaging Spectroscopy

The magnetic field-induced superconductor-insulator-metal transition (SIMT) in partially deuterated $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Br, which is just on the Mott boundary, has been observed using the infrared magneto-optical imaging spectroscopy. The infrared reflectivity image on the sample surface revealed that the metallic (or superconducting) and insulating phases coexist and they have different magnetic field dependences. One of the magnetic field dependence is SIMT that appeared on part of the sample surface. The SIMT was concluded to originate from the balance of the inhomogenity in the sample itself and the disorder of the ethylene end groups resulting from fast cooling.Comment: 5 pages, 5 figures, to appear in Phys. Rev.

Petrology of Chondrule Rims in Yamato-791498 and Asuka-881828, the Least-Altered CR Chondrites in the Japanese NIPR Collection

CR chondrites are a group of car-bonaceous chondrites with well-preserved records of formation of their components in the solar nebula. The CR chondrites have undergone a wide range of aqueous alteration from nearly anhydrous (CR2.8 or CR3.0) to extensive recrystallization of primary minerals, including replacement of coarse-grained silicates in chondrules (CR2.0). At the same time, CRs have experienced only minor thermal metamorphism except for rare CR6 samples. Identifying minimally altered CR chondrites is a priority because they preserve (1) relatively pristine records of the solar nebula and (2) minerals and textures at the beginning stages of aqueous alteration. Here we report the petrologic characteristics of Y-791498 and A-881828 as the least aqueously altered CR chondrites in the Japanese NIPR meteorite collection. Previous studies have shown that fine-grained rims on chondrules are indicators of incipient alteration of primitive CR chondrites, there-fore we focus on rims around chondrules in the two meteorites

Infrared study of spin crossover Fe-picolylamine complex

Infrared (IR) absorption spectroscopy has been used to probe the evolution of microscopic vibrational states upon the temperature- and photo-induced spin crossovers in [Fe(2-picolylamine)3]Cl2EtOH (Fe-pic). To overcome the small sizes and the strong IR absorption of the crystal samples used, an IR synchrotron radiation source and an IR microscope have been used. The obtained IR spectra of Fe-pic show large changes between high-spin and low-spin states for both the temperature- and the photo- induced spin crossovers. Although the spectra in the temperature- and photo-induced high-spin states are relatively similar to each other, they show distinct differences below 750 cm-1. This demonstrates that the photo-induced high-spin state involves microscopically different characters from those of the temperature-induced high-spin state. The results are discussed in terms of local pressure and structural deformations within the picolylamine ligands, and in terms of their possible relevance to the development of macroscopic photo-induced phase in Fe-pic.Comment: 6 pages (text) and 6 figures,submitted to J. Phys. Soc. Jp

Electronic inhomogeneity in EuO: Possibility of magnetic polaron states

We have observed the spatial inhomogeneity of the electronic structure of a single-crystalline electron-doped EuO thin film with ferromagnetic ordering by employing infrared magneto-optical imaging with synchrotron radiation. The uniform paramagnetic electronic structure changes to a uniform ferromagnetic structure via an inhomogeneous state with decreasing temperature and increasing magnetic field slightly above the ordering temperature. One possibility of the origin of the inhomogeneity is the appearance of magnetic polaron states.Comment: 4 pages, 3 figure

Conductance renormalization and conductivity of a multi-subband Tomonaga-Luttinger model

We studied the conductance renormalization and conductivity of multi-subband Tomonaga-Luttinger models with inter-subband interactions. We found that, as in single-band systems, the conductance of a multi-subband system with an arbitrary number of subbands is not renormalized due to interaction between electrons. We derived a formula for the conductivity in multi-subband models. We applied it to a simplified case and found that inter-subband interaction enhances the conductivity, which is contrary to the intra-subband repulsive interaction, and that the conductivity is further enhanced for a larger number of subbands.Comment: 12 pages, no figures. to be published in Physical Review B as a brief repor