Neutron diffraction in a model itinerant metal near a quantum critical point

Neutron diffraction measurements on single crystals of Cr1-xVx (x=0, 0.02, 0.037) show that the ordering moment and the Neel temperature are continuously suppressed as x approaches 0.037, a proposed Quantum Critical Point (QCP). The wave vector Q of the spin density wave (SDW) becomes more incommensurate as x increases in accordance with the two band model. At xc=0.037 we have found temperature dependent, resolution limited elastic scattering at 4 incommensurate wave vectors Q=(1+/-delta_1,2, 0, 0)*2pi/a, which correspond to 2 SDWs with Neel temperatures of 19 K and 300 K. Our neutron diffraction measurements indicate that the electronic structure of Cr is robust, and that tuning Cr to its QCP results not in the suppression of antiferromagnetism, but instead enables new spin ordering due to novel nesting of the Fermi surface of Cr.Comment: Submitted as a part of proceedings of LT25 (Amsterdam 2008

Important role of alkali atoms in A4C60

We show that hopping via the alkali atoms plays an important role for the t1u band of A4C60 (A=K, Rb), in strong contrast to A3C60. Thus the t1u band is broadened by more than 40 % by the presence of the alkali atoms. The difference between A4C60 and A3C60 is in particular due to the less symmetric location of the alkali atoms in A4C60.Comment: 5 pages, revtex, 2 figures, submitted to Phys. Rev. B more information at http://www.mpi-stuttgart.mpg.de/dokumente/andersen/fullerene

Unitary transformations for testing Bell inequalities

It is shown that optical experimental tests of Bell inequality violations can be described by SU(1,1) transformations of the vacuum state, followed by photon coincidence detections. The set of all possible tests are described by various SU(1,1) subgroups of Sp(8,$\Bbb R$). In addition to establishing a common formalism for physically distinct Bell inequality tests, the similarities and differences of post--selected tests of Bell inequality violations are also made clear. A consequence of this analysis is that Bell inequality tests are performed on a very general version of SU(1,1) coherent states, and the theoretical violation of the Bell inequality by coincidence detection is calculated and discussed. This group theoretical approach to Bell states is relevant to Bell state measurements, which are performed, for example, in quantum teleportation.Comment: 3 figure

Stiff Polymers, Foams and Fiber Networks

We study the elasticity of fibrous materials composed of generalized stiff polymers. It is shown that in contrast to cellular foam-like structures affine strain fields are generically unstable. Instead, a subtle interplay between the architecture of the network and the elastic properties of its building blocks leads to intriguing mechanical properties with intermediate asymptotic scaling regimes. We present exhaustive numerical studies based on a finite element method complemented by scaling arguments.Comment: 4 pages, 5 figure

Pengaruh Terapi Musik Gamelan Terhadap Ekspresi Wajah Positif Pada Anak Autis

The purpose of this research was to study the influence of Javanese tradition music therapy (gamelan) on positive face expression of autistic child. The research subject were three children of autism. Method of this research used observation with rating scale. The research subject was selected by purposive sampling. The data analysis used Friedman-test. The result of analysis was chi square (X2)= 6 (

Analisis Indikator Gaya Hidup yang Berhubungan dengan Usia Menarche Remaja Putri

This research aims to determine the lifestyle indicators that related to menarche age of female teenagers. The methodology that used in this research was correlational studies (association relationship) with retrospective approach. The population in this research was all female student in junior high school in Pekanbaru that have been menarche. This research was conducted on 98 female students in 9 junior high schools in Pekanbaru spread over 3 districts in Pekanbaru. Samples were taken from junior high school that the location was in district with cluster sampling method and then simple random sampling method. The tools used questionnaire that the validity and reliability had been tested. The analysis used univariate and bivariate. The univariate analysis explained respondent characteristic and the variable view. The bivariate analysis explained correlation between each variable with chi-square test. The results that there was relationship between exercise habits and stress control with menarche age of female teenagers, with p value is 0,000 and 0,009. For indicators of diet and bed rest showed that there was no relationship with menarche age. Expected for female teenagers can behave in healthy living lifestyle, especially for exercise habits and stress control that related with menarche age