Abstract
The density-driven Mott transition is studied by means of dynamical mean-field theory in the Hubbard-Holstein model, where the Hubbard term leading to the Mott transition is supplemented by an electron-phonon (-ph) term. We show that an intermediate -ph coupling leads to a first-order transition at , which is accompanied by a phase separation between a metal and an insulator. The compressibility in the metallic phase is substantially enhanced. At quite larger values of the coupling, a polaronic phase emerges coexisting with a nonpolaronic metal.
- Received 30 May 2003
DOI:https://doi.org/10.1103/PhysRevLett.92.106401
©2004 American Physical Society