Resistivity and optical conductivity of cuprates within the t-J model
Abstract
The optical conductivity σ(ω) and the dc resistivity ρ(T) within the extended t-J model on a square lattice, as relevant to high- Tc cuprates, are reinvestigated using the exact-diagonalization method for small systems, improved by performing a twisted boundary condition averaging. The influence of the next-nearest-neighbor hopping t' is also considered. The behavior of results at intermediate doping is consistent with a marginal-Fermi-liquid scenario and in the case of t'=0 for ω>T follows the power law σ∝ω-ν with ν∼0.65 consistent with experiments. At low doping ch<0.1 for T<J σ(ω) develops a shoulder at ω∼ω* , consistent with the observed midinfrared peak in experiments, accompanied by a shallow dip for ω<ω* . This region is characterized by the resistivity saturation, whereas a more coherent transport appears at T<T* producing a more pronounced decrease in ρ(T) . The behavior of the normalized resistivity chρ(T) is within a factor of 2 quantitatively consistent with experiments in cuprates.
- Publication:
-
Physical Review B
- Pub Date:
- August 2005
- DOI:
- 10.1103/PhysRevB.72.075108
- arXiv:
- arXiv:cond-mat/0504640
- Bibcode:
- 2005PhRvB..72g5108Z
- Keywords:
-
- 71.27.+a;
- 72.10.-d;
- 74.72.-h;
- Strongly correlated electron systems;
- heavy fermions;
- Theory of electronic transport;
- scattering mechanisms;
- Cuprate superconductors;
- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 8 pages, 10 figures