Search Results

Advanced search parameters have been applied.
open access

Evidence for coupling between collective state and phonons in two-dimensional charge-density-wave systems

Description: We report on a Raman scattering investigation of the charge-density-wave (CDW), quasi two-dimensional rare-earth tri-tellurides RTe{sub 3} (R = La, Ce, Pr, Nd, Sm, Gd and Dy) at ambient pressure, and of LaTe{sub 3} and CeTe{sub 3} under externally applied pressure. The observed phonon peaks can be ascribed to the Raman active modes for both the undistorted as well as the distorted lattice in the CDW state by means of a first principles calculation. The latter also predicts the Kohn anomaly in t… more
Date: February 15, 2010
Creator: Lavagnini, M.; Baldini, M.; Sacchetti, A.; Castro, D. Di; Delley, B.; Monnier, R. et al.
Partner: UNT Libraries Government Documents Department
open access

Is YbAs a heavy Fermion system

Description: Using parameters extracted from a tight binding fit to an ab initio band structure, the specific heat anomaly observed in YbAs around 5 K is computed within the infinite U limit of the degenerate Anderson impurity model. Applying the renormalization procedure derived in variational treatments of the periodic Anderson model, a quasiparticle Fermi surface with strong nesting features and small mass enhancements is obtained. The results suggest that YbAs is not a classical'' heavy Fermion system. … more
Date: August 1, 1989
Creator: Monnier, R.; Degiorgi, L.; Delley, B.; Koelling, D.D. (Eidgenoessische Technische Hochschule, Zurich (Switzerland). Lab. fuer Festkoerperphysik; Paul Scherrer Inst. (PSI), Villigen (Switzerland) & Argonne National Lab., IL (USA))
Partner: UNT Libraries Government Documents Department
open access

Evidence for weak electronic correlations in Fe-Pnictides

Description: Using x-ray absorption and resonant inelastic x-ray scattering, charge dynamics at and near the Fe L edges is investigated in Fe pnictide materials, and contrasted tothat measured in other Fe compounds. It is shown that the XAS and RIXS spectra for 122 and 1111 Fe pnictides are each qualitatively similar to Fe metal. Cluster diagonalization, multiplet, and density-functional calculations show that Coulomb correlations are much smaller than in the cuprates, highlighting the role of Fe metallicit… more
Date: June 11, 2009
Creator: Yang, W. L.; Sorini, A. P.; Chen, C. C.; Moritz, B.; Lee, W. S.; Vernay, F. et al.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen