1996/09/10 by T. Portengen, Th. Ostreich, Th. Östreich +1 · 3 citations
Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Solid-state spectroscopy and crystallography #Spectroscopy and Quantum Chemical Studies #cond-mat
paper · pdf · doi:10.1103/physrevb.54.17452
published as Phys. Rev. B 54 (1996) 17452 · 15 pages, 5 PostScript figures, submitted to Physical Review B
arxiv created 1996/09/10 · openalex publication_date 1996/12/15 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We present a theory of the linear and nonlinear optical characteristics of the insulating phase of the Falicov-Kimball model within the self-consistent mean-field approximation. The Coulomb attraction between the itinerant d electrons and the localized f holes gives rise to a built-in coherence between the d and f states, which breaks the inversion symmetry of the underlying crystal, leading to (1) electronic ferroelectricity, (2) ferroelectric resonance, and (3) a nonvanishing susceptibility for second-harmonic generation. As experimental tests of such a built-in coherence in mixed-valent compounds, we propose measurements of the static dielectric constant, the microwave absorption spectrum, and the dynamic second-order susceptibility.