We have performed sound velocity measurements in (V1-xCrx)2O3 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 c33 compression modulus; this dip sharpens as the critical point is approached. We do not observe signs of criticality on the shear modulus c44, which is consistent with a transition governed by a scalar order parameter, in accordance with the dynamic mean field theory (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.
Physical Review B
- Pub Date:
- August 2011
- Metal-insulator transitions and other electronic transitions;
- Strongly correlated electron systems;
- heavy fermions;
- Condensed Matter - Strongly Correlated Electrons