The spectral properties of the Falicov-Kimball model in the weak-coupling limit

Abstract

The $f$ and $d$ electron density of states of the one-dimensional Falicov-Kimball model are studied in the weak-coupling limit by exact diagonalization calculations. The resultant behaviors are used to examine the $d$-electron gap (${\Delta }_d$), the $f$-electron gap (${\Delta }_f$), and the $fd$-electron gap (${\Delta }_{fd}$) as functions of the $f$-level energy $E_f$ and hybridization $V$. It is shown that the spinless Falicov-Kimball model behaves fully differently for zero and finite hybridization between $f$ and $d$ states. At zero hybridization the energy gaps do not coincide (${\Delta }_d\ne {\Delta }_f\ne {\Delta }_{fd}$), and the activation gap ${\Delta }_{fd}$ vanishes discontinuously at some critical value of the $f$-level energy $E_{fc}$. On the other hand, at finite hybridization all energy gaps coincide and vanish continuously at the insulator-metal transition point $E_f=E_{fc}$. The importance of these results for a description of real materials is discussed.

10 pages, 7 figures, LaTeX

References in corpus (2)

• Exact solution of the multi-component Falicov-Kimball model in infinite dimensions
• Insulator-to-metal crossover induced by local spin fluctuations in strongly correlated systems

Cited by in corpus (1)

• Valence transition behavior of the doped Falicov-Kimball model at nonzero temperatures