Absence of Translational Symmetry Breaking in Nonmagnetic Insulator Phase on Two-Dimensional Lattice with Geometrical Frustration

The ground-state properties of the two-dimensional Hubbard model with nearest-neighbor and next-nearest-neighbor hoppings at half filling are studied by the path-integral-renormalization-group method. The nonmagnetic-insulator phase sandwiched by the the paramagnetic-metal phase and the antiferromagnetic-insulator phase shows evidence against translational symmetry breaking of the dimerized state, plaquette singlet state, staggered flux state, and charge ordered state. These results support that the genuine Mott insulator which cannot be adiabatically continued to the band insulator is realized generically by Umklapp scattering through the effects of geometrical frustration and quantum fluctuation in the two-dimensional system.Comment: 4 pages and 7 figure

Language, culture, and group membership: An investigation into the social effects of colloquial Australian English

Languages are strong markers of social identity. Multiple features of language and speech, from accent to lexis to grammatical constructions, mark speakers as members of specific cultural groups. In the current article, we present two confederate-scripted studies that investigated the social effects of the Australian hypocoristic use (e.g., uggie, uni, derro)—a lexical category emblematic of Australian culture. Participants took turns with a confederate directing each other through locations on a map. In their directions, the confederate used either hypocoristic (e.g., uni) or standard forms (e.g., university). The confederate’s cultural group membership and member prototypicality were manipulated by ethnic background and accent: In a highly prototypical in-group condition, the confederate had an Anglo-Celtic background and Australian English (AusE) accent; in a low prototypical in-group condition, the confederate had an Asian background and AusE accent; and in the out-group condition, the confederate had an Asian background and non-AusE accent. Hypocoristic use resulted in significantly higher participant-rated perceived common ground with the confederate when the confederate was an in-group but not an out-group member, which in some instances was moderated by in-group identification. The results suggest that like accents, culturally significant lexical categories function as markers of in-group identity, which influence perceived social closeness during interaction

Thermodynamic Relations in Correlated Systems

Several useful thermodynamic relations are derived for metal-insulator transitions, as generalizations of the Clausius-Clapeyron and Eherenfest theorems. These relations hold in any spatial dimensions and at any temperatures. First, they relate several thermodynamic quantities to the slope of the metal-insulator phase boundary drawn in the plane of the chemical potential and the Coulomb interaction in the phase diagram of the Hubbard model. The relations impose constraints on the critical properties of the Mott transition. These thermodynamic relations are indeed confirmed to be satisfied in the cases of the one- and two-dimensional Hubbard models. One of these relations yields that at the continuous Mott transition with a diverging charge compressibility, the doublon susceptibility also diverges. The constraints on the shapes of the phase boundary containing a first-order metal-insulator transition at finite temperatures are clarified based on the thermodynamic relations. For example, the first-order phase boundary is parallel to the temperature axis asymptotically in the zero temperature limit. The applicability of the thermodynamic relations are not restricted only to the metal-insulator transition of the Hubbard model, but also hold in correlated systems with any types of phases in general. We demonstrate such examples in an extended Hubbard model with intersite Coulomb repulsion containing the charge order phase.Comment: 10 pages, 9 figure

Metallic Cylinder Reflected Power Measurement For 93.1GHz Frequency Modulated Continuous Wave Radar Calibration

A metallic cylinder is one of the best materials and shapes to calibrate a radar system performance. The measurement of a 4cm diameter and 3cm-height metallic cylinder as a target has been presented for the analysis at the millimeter-wave (mm-wave) spectrum. This experiment was conducted in a real airport environment at Kuala Lumpur International Airport considering clear sky conditions. The measurement was carried out at 93.1 GHz which uses Frequency Modulated Continuous Wave (FMCW) radar to consistently detect the target. The radar cross-section (RCS) of the metallic cylinder is measured with respect to the angle of runway pavement. It is found that the measurements exhibited smaller RCS value with an average of –43.47 dBsm at a longer range compared to –30.16 dBsm at a shorter range with a total change of 13.31 dBsm. The reflectivity characteristics of the radar target, theoretical measurement of the metallic cylinder, its incident angle from the radar target, and measurement evaluation are presented in this paper

Metallic Cylinder Reflected Power Measurement For 93.1GHz Frequency Modulated Continuous Wave Radar Calibration

A metallic cylinder is one of the best materials and shapes to calibrate a radar system performance. The measurement of a 4cm diameter and 3cm-height metallic cylinder as a target has been presented for the analysis at the millimeter-wave (mm-wave) spectrum. This experiment was conducted in a real airport environment at Kuala Lumpur International Airport considering clear sky conditions. The measurement was carried out at 93.1 GHz which uses Frequency Modulated Continuous Wave (FMCW) radar to consistently detect the target. The radar cross-section (RCS) of the metallic cylinder is measured with respect to the angle of runway pavement. It is found that the measurements exhibited smaller RCS value with an average of –43.47 dBsm at a longer range compared to –30.16 dBsm at a shorter range with a total change of 13.31 dBsm. The reflectivity characteristics of the radar target, theoretical measurement of the metallic cylinder, its incident angle from the radar target, and measurement evaluation are presented in this paper

Relic clinopyroxenes and metamorphism of the Motton Spilite of the Leven Hills district, Tasmania

Electron probe analyses of the relic clinopyroxenes and bulk chemicalcompositions of the Motton Spilite greenstones both suggest that they have been derived from basaltic rocks similar to ocean floor tholeiites. The greenstones are considered to have been affected by low-grade metamorphism whose physical conditions corresponded to those of the lower grade part of the glaucophanitic facies

Nonmagnetic Insulating States near the Mott Transitions on Lattices with Geometrical Frustration and Implications for κ\kappa-(ET)2_2Cu2(CN)3_2(CN)_3

We study phase diagrams of the Hubbard model on anisotropic triangular lattices, which also represents a model for $\kappa$-type BEDT-TTF compounds. In contrast with mean-field predictions, path-integral renormalization group calculations show a universal presence of nonmagnetic insulator sandwitched by antiferromagnetic insulator and paramagnetic metals. The nonmagnetic phase does not show a simple translational symmetry breakings such as flux phases, implying a genuine Mott insulator. We discuss possible relevance on the nonmagnetic insulating phase found in $\kappa$-(ET)$_2$Cu$_2(CN)_3$.Comment: 4pages including 7 figure

Ab initio Derivation of Low-energy Model for Iron-Based Superconductors LaFeAsO and LaFePO

Effective Hamiltonians for LaFeAsO and LaFePO are derived from the downfolding scheme based on first-principles calculations and provide insights for newly discovered superconductivity in the family of LnFeAsO$_{1-x}$F$_x$, Ln = La, Ce, Pr, Nd, Sm, and Gd. Extended Hubbard Hamiltonians for five maximally localized Wannier orbitals per Fe are constructed dominantly from five-fold degenerate iron-3$d$ bands. They contain parameters for effective Coulomb and exchange interactions screened by the polarization of other electrons away from the Fermi level. The onsite Coulomb interaction estimated as 2.2-3.3 eV is compared with the transfer integrals between the nearest-neighbor Fe-3$d$ Wannier orbitals, 0.2-0.3 eV, indicating moderately strong electron correlation. The Hund's rule coupling is found to be 0.3-0.6 eV. The derived model offers a firm basis for further studies on physics of this family of materials. The effective models for As and P compounds turn out to have very similar screened interactions with slightly narrower bandwidth for the As compound.Comment: 5 pages, 3 figures, 1 table; to appear in J. Phys. Soc. Jpn. Vol. 77 No.9: Revised version contains corrected table values and discussions of quantitative accuracy of constrained random-phase approximatio