Quantum phonons and the chargedensitywave transition temperature: A dynamical meanfield study
Abstract
We use the dynamical meanfield method to calculate the chargedensitywave (CDW) transition temperature of the halffilled Holstein model as a function of typical phonon frequency in the physically relevant adiabatic limit of phonon frequency Ω much less than electron bandwidth t. Our work is a systematic expansion of the chargedensitywave problem in Ω/t. Quantum phonon effects are found to suppress T_{co} severely, in agreement with previous work on onedimensional models and numerical studies of the dynamical meanfield model in the extreme antiadiabatic limit (Ω~t). We suggest that this is why there are very few CDW systems with meanfield transition temperatures much less than a typical phonon frequency.
 Publication:

Physical Review B
 Pub Date:
 March 2001
 DOI:
 10.1103/PhysRevB.63.115114
 arXiv:
 arXiv:condmat/0008282
 Bibcode:
 2001PhRvB..63k5114B
 Keywords:

 71.45.Lr;
 71.10.w;
 71.10.Fd;
 71.10.Hf;
 Chargedensitywave systems;
 Theories and models of manyelectron systems;
 Lattice fermion models;
 NonFermiliquid ground states electron phase diagrams and phase transitions in model systems;
 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Materials Science
 EPrint:
 8 pages, 4 figures, submitted to Phys. Rev. B, 3 references added