Charge dynamics and optical conductivity of the t-J model

Abstract

The dynamic charge susceptibility and the optical conductivity are calculated in the planar t-J model within the memory function method, working directly in terms of Hubbard operators. The density fluctuation spectrum consists of a damped sound-like mode for small wave vectors and a broad high energy peak ($\sim t$) for large momenta. The study of the optical conductivity shows that electron scattering from spin fluctuations leads to the Drude-frequency dependent relaxation rate which exhibits a crossover from ${\omega }^{3/2}$ behavior at low frequencies ($\omega <2|\mu |$), to a linear $\omega$-dependence for frequencies larger than $2|\mu |$. Due to the spin-polaron nature of charge carriers, extra absorbtions arise starting at a frequency $ω\agt J$. The obtained results are in a good agreement with exact diagonalization studies.

A more detailed discussion on the doping dependence of the results is added. Aspects of the decoupling procedure is clarified and references is slightly modified. Accepted for publication in Phys. Rev. B

References in corpus (8)

• Correlated Electrons in High Temperature Superconductors
• Resistivity as a function of temperature for models with hot spots on the Fermi surface.
• Anomalous Spin and Charge Dynamics of the 2D t-J Model at low doping
• Theory of the density fluctuation spectrum of strongly correlated electrons
• Statics and dynamics of charge fluctuations in the t-J model
• Universal Charge and Spin Response in Optimally Doped Antiferromagnets
• Inverse photoemission in strongly correlated electron systems
• Charge correlations in the weakly doped t-J model calculated by projection technique

Cited by in corpus (10)

• Electrodynamics of Correlated Electron Materials
• Charge dynamics of doped holes in high Tc cuprates - A clue from optical conductivity
• Specific temperature dependence of pseudogap in YBa${}_2$Cu${}_3$O${}_{7-\delta }$ nanolayers
• Dynamic spin susceptibility in the t-J model
• Polaronic features in the optical properties of the Holstein-t-J model
• Dynamical charge susceptibility in layered cuprates: the influence of screened inter-site Coulomb repulsion
• Optical and dc conductivities of cuprates: Spin-fluctuation scattering in the t-J model
• Optical conductivity due to orbital polarons in systems with orbital degeneracy
• Memory Function Approach to Correlated Electron Transport: A Comprehensive Review
• Memory-function approach to the normal-state optical properties of the Bechgaard salt (TMTSF)_2PF_6