1999
Zaanen, J; Feiner, LF; Oles, AM
Classical frustration and quantum disorder in spin-orbital models Tijdschriftartikel
In: MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, vol. 63, nr. 1-2, pp. 140-146, 1999, ISSN: 0921-5107, (7th NEC Symposium on Fundamental Approaches to New Material Phases - Phase Control in Spin-Charge-Orbital Complex Systems, NASU, JAPAN, OCT 11-15, 1998).
Abstract | Links | BibTeX | Tags: orbital sector; Hund's rule; phase diagram
@article{WOS:000081887800023,
title = {Classical frustration and quantum disorder in spin-orbital models},
author = {J Zaanen and LF Feiner and AM Oles},
doi = {10.1016/S0921-5107(99)00064-1},
issn = {0921-5107},
year = {1999},
date = {1999-08-01},
journal = {MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED
TECHNOLOGY},
volume = {63},
number = {1-2},
pages = {140-146},
publisher = {ELSEVIER SCIENCE SA},
address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND},
organization = {NEC Corp},
abstract = {Recently much attention is paid to the role of the orbital degrees of
freedom in transition metal oxides as it remains unclear whether they
can remain in a quantum disordered state at zero temperature. Discrete
symmetry of the orbital sector counteracts the quantum melting, but
especially in doped systems there are signs of dynamical frustration
involving the spin-, charge-, and orbital sector simultaneously. It was
discovered that even the simple Kugel-Khomskii (KK) model, describing
e(g) degenerate Mott-insulators, is characterized by a point of perfect
dynamical frustration on the classical level, reached in the absence of
Hund's rule and electron-phonon couplings. This frustration is lifted on
the quantum level, and the true nature of the ground state is still
unknown. At present there are two proposals: the KCu3 phase, stabilized
by an order-out-of-disorder mechanism; or spin orbital valence bond
phases. It will be argued that at least in the Cu-based systems of this
kind, the electron-phonon coupling is primarily responsible for driving
the systems away from the special point in the phase diagram. (C) 1999
Elsevier Science S.A. All rights reserved.},
note = {7th NEC Symposium on Fundamental Approaches to New Material Phases -
Phase Control in Spin-Charge-Orbital Complex Systems, NASU, JAPAN, OCT
11-15, 1998},
keywords = {orbital sector; Hund's rule; phase diagram},
pubstate = {published},
tppubtype = {article}
}
Recently much attention is paid to the role of the orbital degrees of
freedom in transition metal oxides as it remains unclear whether they
can remain in a quantum disordered state at zero temperature. Discrete
symmetry of the orbital sector counteracts the quantum melting, but
especially in doped systems there are signs of dynamical frustration
involving the spin-, charge-, and orbital sector simultaneously. It was
discovered that even the simple Kugel-Khomskii (KK) model, describing
e(g) degenerate Mott-insulators, is characterized by a point of perfect
dynamical frustration on the classical level, reached in the absence of
Hund's rule and electron-phonon couplings. This frustration is lifted on
the quantum level, and the true nature of the ground state is still
unknown. At present there are two proposals: the KCu3 phase, stabilized
by an order-out-of-disorder mechanism; or spin orbital valence bond
phases. It will be argued that at least in the Cu-based systems of this
kind, the electron-phonon coupling is primarily responsible for driving
the systems away from the special point in the phase diagram. (C) 1999
Elsevier Science S.A. All rights reserved.
freedom in transition metal oxides as it remains unclear whether they
can remain in a quantum disordered state at zero temperature. Discrete
symmetry of the orbital sector counteracts the quantum melting, but
especially in doped systems there are signs of dynamical frustration
involving the spin-, charge-, and orbital sector simultaneously. It was
discovered that even the simple Kugel-Khomskii (KK) model, describing
e(g) degenerate Mott-insulators, is characterized by a point of perfect
dynamical frustration on the classical level, reached in the absence of
Hund's rule and electron-phonon couplings. This frustration is lifted on
the quantum level, and the true nature of the ground state is still
unknown. At present there are two proposals: the KCu3 phase, stabilized
by an order-out-of-disorder mechanism; or spin orbital valence bond
phases. It will be argued that at least in the Cu-based systems of this
kind, the electron-phonon coupling is primarily responsible for driving
the systems away from the special point in the phase diagram. (C) 1999
Elsevier Science S.A. All rights reserved.