Lattice- and spin-polaronic defects in antiferromagnetic halogen-bridged transition-metal chain compounds

Autor:	Huang Xz, Bishop Ar
Rok vydání:	1993
Předmět:	symbols.namesake Bipolaron Materials science Condensed matter physics Hubbard model Exciton symbols Antiferromagnetism Condensed Matter::Strongly Correlated Electrons Electronic structure Raman spectroscopy Polaron Raman scattering
Zdroj:	Physical Review B. 48:16148-16151
ISSN:	1095-3795 0163-1829
Popis:	The results of many-body modeling are reported for polaronic defect excitations in the nickel-based halogen-bridged chain compounds, exemplified by NiBr. One-electron band structures and Raman scattering amplitudes, for electron and hole polarons and bipolarons, triplet excitons, negative, neutral, and positive solitons, are qualitatively described. A singlet exciton is found to be unstable with our model parameters, due to the large on-site Hubbard repulsion. Most significantly, the local defect excitations exhibit a substantial lattice distortion relative to the undistorted antiferromagnetic spin background. The stoichiometric lattice symmetry is therefore broken locally, resulting in Raman activity, which is unexpected on the basis of the stoichiometric ground-state symmetry
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::6f014c193ef198a1159e17483499dc91 https://doi.org/10.1103/physrevb.48.16148 Zobrazit plný text záznamu