Existence of a metallic phase in a 1D Holstein–Hubbard model at half filling

✍ Scribed by Phani Murali Krishna; Ashok Chatterjee

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 291 KB
• Volume: 457
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2007.02.015

✦ Synopsis

The one-dimensional half-filled Holstein-Hubbard model is studied using a series of canonical transformations including phonon coherence effect that partly depends on the electron density and is partly independent and also incorporating the on-site and the nearest-neighbour phonon correlations and the exact Bethe-ansatz solution of Lieb and Wu. It is shown that choosing a better variational phonon state makes the polarons more mobile and widens the intermediate metallic region at the charge-density-wave-spin-density-wave crossover recently predicted by Takada and Chatterjee. The presence of this metallic phase is indeed a favourable situation from the point of view of high temperature superconductivity.