Quantum phonons and the charge-density-wave transition temperature: A dynamical mean-field study
Abstract
We use the dynamical mean-field method to calculate the charge-density-wave (CDW) transition temperature of the half-filled 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 charge-density-wave problem in Ω/t. Quantum phonon effects are found to suppress Tco severely, in agreement with previous work on one-dimensional models and numerical studies of the dynamical mean-field model in the extreme antiadiabatic limit (Ω~t). We suggest that this is why there are very few CDW systems with mean-field 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:cond-mat/0008282
- Bibcode:
- 2001PhRvB..63k5114B
- Keywords:
-
- 71.45.Lr;
- 71.10.-w;
- 71.10.Fd;
- 71.10.Hf;
- Charge-density-wave systems;
- Theories and models of many-electron systems;
- Lattice fermion models;
- Non-Fermi-liquid ground states electron phase diagrams and phase transitions in model systems;
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Materials Science
- E-Print:
- 8 pages, 4 figures, submitted to Phys. Rev. B, 3 references added