22,318 research outputs found

    Optical properties of the charge-density-wave polychalcogenide compounds R2R_2Te5_5 (RR=Nd, Sm and Gd)

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    We investigate the rare-earth polychalcogenide R2R_2Te5_5 (RR=Nd, Sm and Gd) charge-density-wave (CDW) compounds by optical methods. From the absorption spectrum we extract the excitation energy of the CDW gap and estimate the fraction of the Fermi surface which is gapped by the formation of the CDW condensate. In analogy to previous findings on the related RRTen_n (n=2 and 3) families, we establish the progressive closing of the CDW gap and the moderate enhancement of the metallic component upon chemically compressing the lattice

    Probing nucleon strangeness in phi electroproduction

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    We investigate ϕ\phi meson electroproduction to probe the hidden strangeness content of the nucleon. We found that even a small amount of the ssˉs\bar{s} admixture in the nucleon wavefunction can lead to a significant change in several double polarization asymmetries in ϕ\phi electroproduction, which can be tested experimentally at current electron facilities.Comment: 3 pages, 1 figure (2 eps files), LaTeX2e with espcrc1.sty, Talk at the XVI International Conference on Few-Body Problems in Physics (FB16), Taipei, Taiwan, March 6-10, 200

    Mott Transitions of Three-Component Fermionic Atoms with Repulsive Interaction in Optical Lattices

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    We investigate the Mott transitions of three-component (colors) repulsive fermionic atoms in optical lattices using the dynamical mean field theory. We find that for SU(3) symmetry breaking interactions the Mott transition occurs at incommensurate half filling. As a result, a characteristic Mott insulating state appears, where paired atoms with two different colors and atoms with the third color are localized at different sites. We also find another Mott state where atoms with two different colors are localized at different sites and atoms with the third color remain itinerant. We demonstrate that these exotic Mott phases can be detected by experimental double occupancy observations.Comment: 5 pages, 4 figure
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