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14 records were found.

## Lattice softening effects at the Mott critical point of Cr-doped V$_2$O$_3$

We have performed sound velocity measurements in (V$_{1-x}$Cr$_x$)$_2$O$_3$ in the vicinity of the critical point of the first order Mott transition line. The pressure sweeps at constant temperature reveal a large dip in the $c_{33}$ compression modulus, this dip sharpens as the critical point is approached. We do not observe signs of criticality on the shear modulus $c_{44}$ which is consistent with a transition governed by a scalar order parameter, in accordance with the DMFT description of the transition. However, the amplitude of the effect is an order of magnitude smaller than the one obtained from DMFT calculations for a single band Hubbard model. We analyze our results using a simple model with the electronic response function obtained from the scaling relations for the conductivity.

## Universality and Critical Behavior at the Mott transition

Comment: 3 figures

## Incidence of the Tomonaga-Luttinger liquid state on the NMR spin lattice relaxation in Carbon Nanotubes

Comment: 5 pages, 4 figures

## Spin Dynamics at the Mott Transition and in the Metallic State of the Cs_{3}C_{60} Superconducting Phases

We present here ^{13}C and ^{133}Cs NMR spin lattice relaxation T_{1} data in the A15 and fcc-Cs_{3}C_{60} phases for increasing hydrostatic pressure through the transition at p_{c} from a Mott insulator to a superconductor. We evidence that for p>> p_{c} the (T_{1}T)^{-1} data above T_{c} display metallic like Korringa constant values which match quantitatively previous data taken on other A_{3}C_{60} compounds. However below the pressure for which T_{c} goes through a maximum, (T_{1}T)^{-1} is markedly increased with respect to the Korringa values expected in a simple BCS scenario. This points out the importance of electronic correlations near the Mott transition. For p > p_{c} singular T dependences of (T_{1}T)^{-1} are detected for T >> T_{c}. It will be shown that they can be ascribed to a large variation with temperature of the...

## Mott transition, antiferromagnetism, and unconventional superconductivity in layered organic superconductors

Comment: 4 pages, 6 figures, Revtex

## 1/T_1 nuclear relaxation time of \kappa-(BEDT-TTF)_ 2 Cu [N(CN)_2] Cl : effects of magnetic frustration

We study the role played by the magnetic frustration in the antiferromagnetic phase of the organic salt \kappa-(BEDT-TTF)_ 2 Cu [N(CN)_2] Cl. Using the spatially anisotropic triangular Heisenberg model we analyze previous and new performed NMR experiments. We compute the 1/T_1 relaxation time by means of the modified spin wave theory. The strong suppression of the nuclear relaxation time observed experimentally under varying pressure and magnetic field is qualitatively well reproduced by the model. Our results suggest the existence of a close relation between the effects of pressure and magnetic frustration.

## Hole redistribution in Sr\_(14-x)Ca\_xCu\_24O\_41 (x = 0, 12) spin ladder compounds: ^63Cu and ^17O NMR study under pressure

Comment: 9 pages (Revtex), mai 2005

## NMR Evidence for Gapped Spin Excitations in Metallic Carbon Nanotubes

Comment: 4 pages, 3 figures. Submitted to PRL on 12 August 2005

## (Sr/Ca)_{14}Cu_{24}O_{41} spin ladders studied by NMR under pressure

Comment: 15 pages Latex, 13 figures. to be published in Eur.Phys.Jour.B,2002

## Mott transition and transport crossovers in the organic compound $\kappa-(BEDT-TTF)_2 Cu[N(CN)_2] Cl$

Comment: 4 pages, 6 figures