Naslov
Edge and Ultragap States in Mixed-Halide MX-Chains

Autori
Saxena, A. ; Batistić, I. ; Bishop, A.R. ; Gammel, J.T.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Bulletin of Americal Physical Society / - : American Physical Society, 1991, 783-783

Skup
APS March meeting

Mjesto i datum
Cincinnati (OH), Sjedinjene Američke Države, 18.03.1991. - 22.03.1991

Vrsta sudjelovanja
Poster

Vrsta recenzije
Podatak o recenziji nije dostupan

Ključne riječi
Edge and Ultragap States, halogen-bridged transition metal complexes

Sažetak
Theoretical modeling of mixed-halide, halogen-bridged transition metal complexes, (M=Pt ; X, X'=Cl, Br, I) are described in terms of a 3/4-filled, two-band, discrete, tight-binding, extended Peierls-Hubbard model. A mean-field approximation is used for the electronic structure and a direct-space random-phase approximation is used to treat quantum lattice fluctuations. The interaction of phonons with electron-hole pairs is incorporated to calculate infrared and Raman spectra. In addition to the usual gap states, new local vibrational modes are found well to the blue of the band gaps of both constituent PtX species. These ultragap states are attributed to edge states at the junction between chain segments. Moreover, we find interpenetration of CDWs at the edge, the polarization of the MX_2 unit near the edge, and charge transfer across the edge. The photoexcitation and doping of these systems exhibit selectivity for the location of polaronic excitations, depending on the charge and nature of the excitation, as well as the combination of X, X' and the energy of photoexcitation. These results are consistent with recent resonance Raman experiments on mixed-halide MX complexes.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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