Charge states of strongly correlated 3d oxides: from typical insulator to unconventional electron-hole Bose liquid / Moskvin A. S. // LOW TEMPERATURE PHYSICS. - 2007. - V. 33, l. 2-3. - P. 234-244.

ISSN/EISSN:

1063-777X / нет данных

Type:

Article; Proceedings Paper

Abstract:

We present a model approach to describe charge fluctuations and different charge phases in strongly correlated 3d oxides. As a generic model system we consider that of centers each with three possible valence states M-0,M-+/- described in the framework of an S=1 pseudospin (isospin) formalism by an effective anisotropic non-Heisenberg Hamiltonian which includes two types of single-particle correlated hopping and also the two-particle hopping. Simple uniform mean-field phases include an insulating monovalent M-0 phase, mixed-valence binary (disproportionated) M-+/- phase, and a mixed-valence ternary ({''}under-disproportionated{''}) M-0,M-+/- phase. We consider the first two phases in more detail, focusing on the problem of electron-hole states and different types of excitons in the M-0 phase and the formation of electron-hole Bose liquid in the M-+/- phase. The pseudospin formalism provides a useful framework for revealing and describing different topological charge fluctuations, such as, in particular, domain walls or bubble domains in antiferromagnets. Electron-lattice polarization effects are shown to be crucial for the stabilization of either phase. All the insulating systems such as M-0 phase are subdivided to two classes: stable and unstable ones with respect to the formation of self-trapped charge transfer (CT) excitons. The latter systems appear to be unstable with respect to the formation of CT exciton clusters, or droplets of the electron-hole Bose liquid. The model approach suggested is believed to apply to the description of the physics of strongly correlated oxides such as cuprates, manganites, bismuthates, and other systems with charge transfer excitonic instability and/or mixed valence. We briefly discuss an unconventional scenario of the essential physics of cuprates which implies their instability with respect to the self-trapping of charge-transfer excitons and the formation of electron-hole Bose liquid. (c) 2007 American Institute of Physics.

Author keywords:

PHASE-SEPARATION; PHOTOINDUCED PHASE; SUPERCONDUCTORS; SYSTEM; METAL; CRYSTALS; EXCITONS; LATTICE; SPIN

DOI:

10.1063/1.2719961

Web of Science ID:

ISI:000245900300023

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	FEB-MAR
Note	16th Ural International Winter School on Physics of Semiconductors, Kyshtym, RUSSIA, FEB 27-MAR 04, 2006
Organization	Russian Acad Sci, Inst Met Phys, Ural Div
Publisher	AMER INST PHYSICS
Address	CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA
Language	English
Keywords-Plus	PHASE-SEPARATION; PHOTOINDUCED PHASE; SUPERCONDUCTORS; SYSTEM; METAL; CRYSTALS; EXCITONS; LATTICE; SPIN
Research-Areas	Physics
Web-of-Science-Categories	Physics, Applied
Author-Email	alexandr.moskvin@usu.ru
Number-of-Cited-References	37
Usage-Count-Last-180-days	3
Usage-Count-Since-2013	7
Journal-ISO	Low Temp. Phys.
Doc-Delivery-Number	159XE