Optical conductivity of strongly correlated electron systems

R Eder*, P Wrobel, Y Ohta

*Corresponding author for this work

    Research output: Contribution to journalArticleAcademicpeer-review

    16 Citations (Scopus)

    Abstract

    We present an exact-diagonalization study of the frequency- and wave-vector-dependent conductivity sigma(q,omega) in small clusters in the two-dimensional t-J model. Unlike the related dynamical density correlation function, sigma(q=0,omega) in the underdoped regime has the exchange constant J as its characteristic energy scale and is dominated by a resonancelike excitation with frequency similar to 1.7 J. We interpret this as transition to a p-like excited state of a spin-bag-type quasiparticle (or, alternatively, a tightly bound spinon-holon pair) and show that a simple calculation based on the string picture explains the numerical results semiquantitatively. For doping levels greater than or equal to 25% t remains the only energy scale of sigma(q=0,omega).

    Original languageEnglish
    Pages (from-to)11034 - 11037
    Number of pages4
    JournalPhysical Review B
    Volume54
    Issue number16
    DOIs
    Publication statusPublished - 15-Oct-1996

    Keywords

    • T-J MODEL
    • SPIN
    • DYNAMICS
    • HUBBARD
    • CHARGE

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